TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 280: Seven Keys to Building a Robust Research Program identifies attributes necessary to build and maintain a robust research program.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=3279

This synthesis report will be of interest to officials of municipal, regional, and statewide transportation and law enforcement agencies who are responsible for roadway incident diversion practices. It will also be of interest to others who interact with these agencies to achieve a better understanding of the processes, barriers, and technologies associated with alternate route plan development and deployment. This report presents state-of-the-practice information about the development and implementation of roadway incident diversion practices. It documents specific trends in the practice, and in examining individual practices, identifies unique plans, processes, and technologies from which other agencies may find useful applications. This TRB report addresses a broad list of topics associated with roadway incident diversion and profiles successful incident diversion practices, as reported by surveyed agencies. In particular, it focuses concern on alternate route plans for random incidents, those resulting in nonrecurring congestion.  The report for this topic can be purchased at http://www.trb.org/news/blurb_detail.asp?id=3280

This synthesis will be of interest to pavement construction, maintenance, design, and materials engineers; pavement contractors; and others interested in the use of open-graded friction course (OGFC) mixes. It describes the current state of the practice on the use of OGFC mixes, including information regarding design, materials, construction, maintenance, and rehabilitation strategies. Alternative treatments to traditional OGFC are also identified and discussed. Information was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search to gather additional insight into North American and European practices. This TRB report describes the recent performance of North American OGFC mixes and European porous asphalt by identifying benefits and stress indicators. A new generation of OGFC mixes has evolved over the last 5 years with changes that have been reported to dramatically improve performance. This synthesis describes new materials and design methods being used, as well as the applicability of the new generation of open-graded mixtures to North American use.  Th report for this topic can be purchased at http://www.trb.org/news/blurb_detail.asp?id=3275

This synthesis report will be of interest to DOT chief administrative and information officers, information technology staff, and project managers and their supervisors. It describes the current state of the practice for DOT project management information systems, as well as current best practices across other industries. Several case studies and an appendix chapter on change: definition and implementation, role of personnel, processes, and cost are also provided. This TRB report describes the processes used to develop and implement automated project management information systems, the sources of software in use, and the extent of any modifications necessary for commercial projects to fit DOT business needs. It also describes the operating environments for systems in use and the capabilities and limitations of the systems used to track multiple projects and information sources. In addition, information on system capabilities and deficiencies in project communications, report and problem solving, the necessary resources required to implement and maintain each automated system, the length of time each system has been in place, and future plans for long-term enhancement, modifications, or enhancements is included.  The report for this topic can be purchased at http://www.trb.org/news/blurb_detail.asp?id=3277

Divided roadways separated by narrow medians in urban, rural, and suburban areas can impact traffic operations and safety. This synthesis will: locate and document available literature, resources, and practical experience that median width has on the operation of larger vehicles; identify and report on specific traffic operation and safety concerns (e.g., left turns, U-turns, sight distance, storage needs, and increased vehicle size); and summarize the reported effectiveness of the various methods, techniques, and strategies (e.g., design criteria, routing, intersection control, access management, land use planning, and local ordinances) used to address the identified concerns. To the extent possible, international experience will be sought. The final report will be published as NCHRP Synthesis 281.

Many state DOTs and local transportation agencies are increasing the percentage of design work done by outside consultants forces. The reasons for using consultants to perform design work are varied, but it is often a result of increased public/legislative pressure to downsize government at the same time the design workload is increasing. Design work encompasses all pre-construction activities. This synthesis will report on the state-of-the-practice regarding the use of consultant forces for DOT design work. Synthesis 137 will be consulted for background information. The synthesis has been published.

In the mid-1970's, the TRB Committee on Maintenance Equipment recommended that a synthesis be prepared to collect the best equipment management practices from around the country. The results of that effort were published in NCHRP Synthesis 52, "Management and Selection Systems for Highway Maintenance Equipment" (1978). The information has become dated due to changes in practice and advancements in information technology. Therefore, this synthesis will be an update of Synthesis 52. This update of Synthesis 52 will include items and issues covered in the existing document. This synthesis will be based on information from a literature search and review and a survey of North American practice. A more limited survey and search of international operations, as well as particularly innovative commercial practices are also required. Case studies to document specific examples of successful practice are to be included. These may include examples of similar concerns shared by other modal fleet managers. The synthesis is in the publishing phase and should print in late April or early May.

This synthesis will provide an overview of the current and emerging methods to measure the in-situ mechanical properties of subgrade soils for highway pavements. "Mechanical properties" will encompass engineering properties related to resilient modulus, modulus of subgrade reaction, shear strength, and other stiffness measures. The synthesis will include, but not be limited to identifying: existing and emerging methods for measuring in-situ soil subgrade mechanical properties; relationships between in-situ soil subgrade and laboratory mechanical properties; environmental effects on in-situ soil subgrade mechanical properties; effect of existing pavement layers on the measurement of subgrade properties; the use of the measured soil subgrade mechanical properties in pavement design/evaluation procedures, including case studies; and new applications or improvements to existing in-situ soil test methodology to support the use of mechanistic/stochastic-based pavement design procedures. The synthesis has been published.

This synthesis summarizes systems engineering processes and methodologies, including those which have been developed and used by transportation agencies. It reports on the traffic engineering community's experience with various systems engineering approaches. Major aspects of the synthesis study include a definition of systems engineering and identification of the general processes, steps, and methodologies commonly used in the industry and relation of these processes to traffic signal ystems. The document has been published.

This synthesis will document the state of the practice, examples of successful practice, and key research needs for the multimodal aspects of statewide transportation planning. This will include information on the evaluation processes and criteria used, implementation, identification of stakeholders and their involvement in multimodal planning and decision making, and how states have successfully dealt with multimodal planning issues associated with modes that they do not own or operate. In addition, information on innovative data collection and analytical methods, how multimodal planning has balanced capital and operating needs, how statewide multimodal plans are affecting programming and budgeting decisions, and how and to what extent are the multimodal aspects of statewide and metropolitan/regional planning processes connected will be included. Finally, information on the greatest needs and impediments that states face in being able to do better statewide multimodal planning will be sought. The synthesis was published in August 2000.

Federal and state transportation agencies, MPOs, local governments, and other organizations are placing an increased emphasis on corridor management. Corridor management responds to the need to enhance the safety and performance of transportation corridors using planning, public policy, programs, and partnerships. It addresses both multimodal transportation and land use issues. This synthesis will identify and discuss the many definitions and approaches (including the tools and techniques) used to implement corridor management at the state, regional, and local level. Case studies on the use of multiple techniques to accomplish corridor management are required. Conclusions on their application will also be included. The synthesis was published in October 2000.

In anticipation of highway construction projects, some state DOTs are incorporating innovative management-based actions in their activities. This is being done in an effort to reduce total project time typically associated with project development, including the acquisition and clearance of Right-of Way (ROW). There is a need to alert state DOT officials and staff to the necessity of responsible overall project management, emphasizing those problems associated with the delivery of ROW. This synthesis of current practice will study successful experiences in project development, including innovative solutions. Successful state practices will be profiled and information presented. The synthesis was published in December 2000.

State DOTs and MPOs have need to measure the economic development impacts from transportation investments. To meet this need, many approaches are available. This synthesis of existing practice will summarize available research and studies on economic development impacts form transportation investments, and the techniques that states and MPOs use and the rationale for conducting the analysis. The synthesis was published in October 2000.

The synthesis shall provide background information and report on the types of drowsy-driving countermeasures in use by state DOTs and others (e.g., ATA, AAA, CVSA). This will include countermeasures to ensure that drivers do not operate vehicles in fatigued state, as well as countermeasures designed to detect and counteract drowsy driving when it does occur. The reported effectiveness, advantages/disadvantages, and prevalence of each identified countermeasure will be documented. Information on devices under research and in development will be discussed, including estimates of availability. The synthesis was published in July 2000.

The Federal Highway Administration (FHWA), in cooperation with the American Association of State Highway and Transportation Officials (AASHTO) and the Association of Metropolitan Planning Organizations (AMPO), is conducting a strategic reassessment of the Highway Performance Monitoring System (HPMSO). This synthesis will document current arrangements among state DOTs, MPOs, and regional and local agencies to collect and share data. The key elements to be surveyed include institutional (contractual and administrative) arrangements, use of data, data sharing, cost and resource requirements, technical capabilities/barriers, implementation processes, data quality and compatibility, as well as successes, failures, and difficulties. It is anticipated that a number of case studies of successful partnerships will be identified and documented in detail. The synthesis was published in October 2000.

Bridge deck movement (e.g., expansion) joints used in the United States consist of wide variety of materials, designs, and construction methods. This synthesis will collect information on their use and report on the performance of the more commonly used bridge deck joint materials and systems. State of the art information on large joints (movement range 6 inches or greater, including modular), international practice, examples of effective agency standard design details and specifications, and a glossary of terms will also be included. The initial Consultant resigned and a new consultant is on board. The new Consultant contract began on April 1, 2001. Panel and 20-5 comments were received on the second draft, and the consultant submitted the final draft on December 17, 2002. The consultant provided response to these on 4/22/03. After extensive revision by staff, these responses and the final document were submitted for SNO review on June. Published 8/29/03.

Improved quality assurance (QA) strategies are needed by state DOTs to enhance their ability to ensure cost effective, high quality bridges and structures. This synthesis will report on the experiences of transportation agencies and other construction industries, both foreign and domestic, in the application of quality assurance strategies for conventional and high performance structural materials in highway structures. It will identify QA strategies proven effective for structures and materials, as well as those that are not effective. In addition, it will provide information to states initiating or revising quality programs for their critical structural components. This information includes state processes for quality assurance and contractor processes for quality control on new and retrofit construction, using conventional and/or innovative materials. A new consultant was employed to complete a second draft. This was delivered April 24,2002, and, after review, was forwarded to the panel and 20-5 Committee for final review on May 5, 2002. The 20-5 and committee comments were overnighted to the consultant on August 1, 2002, with a due date of August 21 for the final revised draft. Consultant promised delivery by 10/02, 10/15, 12/11, and 12/29. The consultant has not provided the revised final draft. Because the material in this synthesis has become outdated, it is recommended that the highlights of the contents be published as a Research Results Digest. RRD 274 has been published, 9/3/03.

Effective removal of water from pavement systems has been proven to help achieve pavement service life. Maintenance of edgedrains is therefore important at the outlets and within. The primary purpose of this synthesis is to identify practices and procedures for maintaining the edgedrain system (I.e., outlet, headwall, connection, and longitudinal pipe). A secondary purpose of the synthesis is to identify design and construction procedures that will reduce and facilitate the maintenance of edgedrains. The synthesis was published in July 2000.

This synthesis will collect information and report on the issues pertaining to pavement friction characteristics, including aggregate and mix design properties, methods of testing and monitoring, and evaluation of pavement friction properties after construction or rehabilitation. A literature search of domestic and international sources and a survey of state and provincial transportation agencies will be conducted. From international sources, information on the International Friction Index is of particular interest. The synthesis was published in December 2000.

Construction and maintenance operations inevitably require work forces to occupy the roadway. With travel demand at or near congestion levels, methods of limiting the time on the road are being applied internationally. These methods include preconstruction and construction processes for minimizing lane occupancy in order to mitigate impacts on the public. This synthesis will address the techniques for reducing lane occupancy as a method for achieving this objective. Background information will be provided with regard to program and policy-related decision-making, design and contractual issues, economic impacts, and the consideration given to regional traffic systems within which the projects are addressed. Specific information regarding lane occupancy will also be addressed. The synthesis was published in December 2000.

During the last decade, there has been considerable research on all aspects of geometric design affecting how roadways are designed, how they operate, and ultimately, the safety of these facilities. This synthesis will critically review and selectively summarize the geometric design research since 1990, particularly research with safety and operational implications. It will be directed toward national, state, and local geometric design policy-makers and mid-level managers. Areas to be addressed include, but are not limited to the following: design speed, controls and criteria (e.g., definitions, vehicles, users), horizontal alignment, vertical alignment, cross section (i.e., right-of-way to right-of-way), intersections, interchanges, access management, and design consistency. The synthesis has been published.

Over the last decade, significant progress has been made in establishing statistical relationships between vehicle crashes and key driver, engineering, and environmental factors; in assessing the safety effect of certain engineering measures; and in identifying potential crash locations. This synthesis effort will survey the literature, state and federal transportation agencies, universities, and other research agencies in order to document the current state of the practice, including, but not limited to the following: traditional and new methods for data management and analysis used by highway safety analysts and researchers; potential limitations of these methods; methods for overcoming limitations affecting transportation safety related research and decision-making previously identified; use of “off-the-shelf,” proprietary, or user developed software; identify the knowledge, training, and skills necessary to improve the state-of-the-practice; and identify future research and development needs. The synthesis was published in October 2001.

The condition of buried culverts and storm sewers (pipes) is an item of concern to DOT, county, and municipal engineers. It is often necessary for engineers to require that pipe condition be assessed and that consideration be given to rehabilitation or replacement. This synthesis will locate and document methods currently being used in the US and internationally to assess pipe condition and select appropriate repair methods. Rehabilitation methods will be documented, including case histories where structures have been reconditioned. Temporary and permanent solutions for structural stabilization are of interest, including the immediate problem of maintaining traffic while repairing the pipe. This study will include plastic, concrete, and metal pipes, along with system appurtenances such as drainage inlets, manholes, junction boxes, and headwalls. The study will not include cast-in-place structures or those defined as bridge structures. The final panel and 20-5 Committee review comments were received, and the consultant submitted his final revised draft on May 10, 2002. SNO approval was received on Sept 20, 2002, and the draft has been submitted for publication

This synthesis will survey current national and international uses of performance measures for evaluating the effectiveness and impact on transportation RD&T programs. The synthesis will include a literature review and a survey of practice. Sources of information will include, but not be limited to state DOTs, the US DOT, and university and private sector measures relevant to transportation RD&T programs. The synthesis will identify: the various kinds of performance measurements being used, how they are developed, how effective the measures are in evaluating individual RD&T transportation programs, the commonality of measures across various programs, and best practices. The synthesis is scheduled for publication on 1/10/02.

The purpose of the synthesis is to summarize and collate existing information, data and algorithms on the state of the practice activities related to the collection of global positioning system (GPS) data, data smoothing and map matching. The focus of the synthesis is the use of kinematic GPS data and its integration into a geographic information system (GIS). Examples of kinematic applications include speed surveys, travel surveys and fleet monitoring analysis. The synthesis report will include information on existing standards, protocols, and new developments in positioning, including cellular technology. The synthesis final draft has been reviewed by the 20-5 committee, revised by the consultant and has been prepared for publication. SNO approval received, and publication of #301 completed.

This synthesis will present examples of successful external and internal research partnerships between all sectors that can be used for transportation research. Items of interest include, but are not limited to, guidelines (e.g., check lists, MOUs), technologies (e.g., communications), and mechanisms (e.g., legislation, institutional and funding arrangements) for implementation. Issues such as patent rights for new products or processes, residual interests/intellectual property rights and other possible conduits for successful implementation of results are also of interest. In addition, strategies for addressing barriers to successful partnerships will be presented. 20-5 review is complete. Submitted for SNO approval on 11/27, and for publication on 12/31/2002. Published May 15, 2003.

This synthesis will document pavement marking practices in the U.S., Canada, and Europe. Other relevant locations will also be considered. This will be done for long-term applications. The synthesis will highlight current and best practices as reported by transportation agencies and help identify future developments of pavement marking systems. How these practices relate to the MUTCD will also be documented. To be published Jan. 9, 2003.

It is of interest to know what factors enable transportation agencies to respond to the evolution of information and communication technologies. This synthesis will review key literature sources and survey state transportation agencies to collect information on agency experience. This will include, but will not be limited to the following: descriptions of the information and communications technology components of agency strategic plans, what changes in organizational structure have or will occur due to implementation of the information and communications technologies, how the information and communications technologies are being managed, what type and kind of technologies are being used, what resources are being dedicated to the implementation and operation of these technologies, including prioritization and allocation, and what has been done to make technology innovation part of the agency culture. The document was published in August 2001.

This synthesis will identify available truck trip generation data. Trip rates associated with economic activities and land uses are of particular interest. Information will include, but not be limited to, the following: office/service (e.g., office campuses, CBDs), retail (e.g., “big box,” mixed use, and malls), industrial (e.g., light, heavy, and high tech), reload/transload centers (e.g., ports, warehouses/distribution centers, rail terminals, airports), for-hire truck facilities (e.g., LTL, TL, specialized, truck stops), integrated express carrier sorting facilities and post offices, waste collection, mining, construction-related activities, and special generators (e.g., convention centers, sports facilities). The validity of the data, collection methods and challenges, and the organizational sources and attitudes toward sharing data will also be addressed. State planning entities and selected MPOs and local jurisdictions will be contacted for information. Private sector, academic, and other sources will also be contacted to obtain truck trip generation rate data. Studies conducted within the last decade are of specific interest. The synthesiswas published in December 2001.

Configuration management (CM) is a necessary process in the planning, design, implementation, integration, and operation of traffic control systems. This synthesis will summarize the field of literature and survey transportation agencies that have developed and used CM and CM plans. It will report on the scope of issues included in agency plans, profile successful agency procedures, and identify additional information (e.g., potential further study, training, technical guidance) needed by transportation agencies to facilitate the successful use of CM. The synthesis has been published.

Central cities depend on funding and support from both the state and Federal government. The ability for central city officials to participate in regional, state, and federal transportation planning, regulatory, and policy decisions varies greatly. City officials desire increased participation, recognition of local context, and cooperative efforts. This synthesis will document various relationships and constructs between large central cities, MPOs, states, the federal government, and other entities to identify practices proven successful in furthering the capital, operations, and maintenance needs of their transportation systems. These cities were previously identified in “Transportation Issues in Large U.S. Cities,” TRB Conference Proceedings 18. The synthesis is in the final stage of the publication process.

This synthesis documents the current practices of transportation agencies as they implement ecological mitigation measures for highway projects as they apply to aquatic wetland, and riparian habitats. It summarizes available information on the types of ecological impacts incurred by highway projects and the methodologies used to assess these impacts, procedures for determining the need for mitigation and monitoring, types of mitigation implemented for different impacts and how mitigated sites are monitored, methodologies for the evaluation of mitigation success or failure, and the costs of mitigation. The synthesis document has been published.

It is nationally recognized that commercial motor vehicle operators frequently can not find adequate, safe parking for rest purposes. Because of the parking shortages and limits on stays in public facilities, truck drivers may be creating unsafe situations by parking on roadway access ramps and shoulders to obtain adequate rest. This synthesis will survey state DOTs, other public and private stakeholders, and existing literature to determine what states are doing to address the problem of limited public and private truck rest facilities. Detailed case studies will be developed to offer additional insight. The Consultant delivered the synthesis first draft. As it was in very good order, the panel voted to conduct its review by mail, without a second panel meeting. Panel comments have been transmitted to the consultant, and the second draft was received in mid-September. 20-5 and panel comments were sent to the consultant on Dec. 31, 2002. A revised final draft was received in February 2003, and was forwarded for SNO review on March 7, 2003. The report is in production.

Many states are seeing significant increases in the number of trucks on their roadways. Truck traffic poses many challenges for state Departments of Transportation (DOTs), Metropolitan Planning Organizations (MPOs), and other transportation organizations. Many states are developing strategies for addressing the associated challenges . This synthesis, based on surveys of state DOTs, a limited number of MPOs and other transportation agencies, and the literature, will identify strategies that are in use or being proposed for managing increased truck traffic. The final document has been printed.

This synthesis will collect and document information from local, state, and federal agencies; international sources; and others regarding crash experience at intersections with red light camera installations. Also of interest are the area wide safety effects of red light cameras. The synthesis will include information on possible changes in crashes, crash type, and severity. Reported practices for measuring changes in crashes associated with red light camera enforcement will be documented so that readers of the synthesis can understand the methods employed and any benefits derived. SNO approval has been received. The synthesis has been published.

Full-scale/accelerated pavement test (APT) programs have been conducted both nationally and internationally for more than 30 years. These programs have generated significant findings/benefits with regard to pavement design, analysis, evaluation and construction practices. The objective of this synthesis is to document and summarize the significant findings from the various experimental activities associated with full-scale/APTs. The focus will be on reported findings and on their application to research and practice, not on the details of the facilities and equipment. In addition to the synthesis of findings, actual and potential benefits to the U.S. pavement community will be addressed. The Consultant has submitted the synthesis first draft. The panel reviewed this and provided extensive comments at their second meeting on March 15, 2002. Second draft was received October 30, 2002. For a synthesis, it is a very large, comprehensive document. It was submitted to the 20-5 committee for review on 12/20/02, as the first synthesis to be web-reviewed by the oversight panel. 20-5 and panel comments were sent to the consultant on March 3, 2003. The final draft was delivered in mid-August. Editing is complete, and SNO approval. Publication was in February n January 2004.

Driveway permitting practices vary widely from state to state. This synthesis will survey state departments of transportation, selected local agencies, and the literature to: summarize driveway-permitting practices for new development, re-development, and highway projects; document problems and benefits of permitting practices; summarize the impacts of driveway permitting practices on safety, operations, maintenance, land use, businesses, and land value; identify obstacles impeding improvements (e.g., legal issues) to driveway permitting practices and actions to overcome them; and summarize lessons learned. The final document has been published.

This synthesis will collect information on and document the practices that agencies use to measure and articulate the benefits of highway system maintenance and operations. This will include the benefits of system preservation and the impacts of deferred maintenance. Of particular interest are the methods used by agencies to effectively communicate the benefits of system maintenance and operations with those in the political process and the general public. The Consultant submitted the first draft in March 2002, and a 2nd panel meeting was held June 17, 2002 to review the draft. The panel provided extensive comments and guidance for revising the draft. The second draft was received October 31, 2002. It was returned to the consultant by staff for more work. The revised second draft has been received and reviewed by the panel and 20-5 committee. Comments have been forwarded to the consultant. Final draft received 12/25/03 and forwarded to editing. SNO approval has been received and publication is expected by August 1, 2004.

This synthesis will summarize the practices used by state transportation departments, several metropolitan planning organizations, and a few cities and counties concerning highway operation performance measures and associated data collection (e.g., link travel times, duration of congestion, reliability, LOS, seasonal road closures, recurring and non-recurring delays). How they are collected and put to use, their relative strengths, weaknesses, and the usefulness of these measures for various audiences and purposes will be documented. Successful practices will also be highlighted using agency profiles. The synthesis is in publication.

There is a nationwide need to encourage counties and cities to improve the overall sufficiency rating of their structure population. A synthesis of the existing practices and processes used to satisfy reasonable operating standards for off-system bridge and approach roadways is needed. The synthesis will survey state Departments of Transportation (DOTs), local agencies, and the literature to document the practices that lead to the most economical, safe and functional, off-system bridges. These bridges are defined as those under local jurisdiction. The consultants delivered the first draft on June 24, 2002. A second panel meeting was held on August 5, 2002 to review the draft, and the panel requested extensive revisions. The second draft was delivered April 15. 20-5 and committee comments were sent to the consultant on 8/12. The final draft was delivered 11/3/04, and is in editing. Publication has been held up while the author responds to editorial queries. SNO approval has been received and publication is expected by August 15, 2004.

Special events are an important and frequent part of transportation system operations. They include sporting events, parades, national conventions, international summits, music festivals, fairs, or other planned events. To optimize the performance of the transportation system during special events, agencies plan and coordinate the delivery of transportation services and operations in advance. This synthesis will report the state of the practice of transportation planning and management of special events. Specifically, it will identify how agencies are planning, coordinating services, and managing the overall transportation system for these periods. The Consultant submitted the synthesis first draft. The panel decided that the draft is complete enough to be reviewed by mail. Panel comments were forwarded to the consultant, who delivered the second draft on April 5, 2002. 20-5 review and SNO review has been completed, and the report was published in March 2003.

Contract change orders, contract delays and claims, and extra and force account work often cause transportation agencies to calculate additional amounts of compensation to be paid out for home office overhead (general and administrative, G&A). This synthesis will document how state departments of transportation (DOTs) are compensating contractors for unabsorbed home office overhead for contract delays. It will identify the methods and percentages currently being used and report on the advantages and disadvantages of each method of compensation. The Consultant submitted the synthesis first draft, and the second panel meeting was held April 5, 2002. The second draft was received in July 2002, and was submitted to 20-5 review in September 2002. 20-5 comments were received Dec. 2, 2002 and were forwarded to the consultant. The final draft was delivered and SNO approval was received March 19. p:ublished July 1, 2003..

The development, operation, and maintenance of roadways can affect wildlife in every part of the country. These effects include a loss of wildlife habitat, fragmentation, mortality, and increased competition. Roadway development choices made in response to population growth can affect many, if not all, wildlife species. This synthesis will summarize existing information related to roadway planning, design, construction, and maintenance practices being used nationally and internationally, successfully and unsuccessfully, to accommodate wildlife ecology. The final draft was submitted to the 20-5 committee. The consultant addressed their comments in a revised final draft, which was approved by the SNO. The report was sent to publication on July 30, 2002, and published in November..

Transportation construction projects involve many types of insurance coverage such as Workers’ Compensation, General Liability, Builder’s Risk, and Professional Liability, to name a few. One of the ways that owners are attempting to manage the risks is to engage in what are called Owner Controlled Insurance Programs (OCIPs) or "wrap-up" insurance coverage. This synthesis will provide owners with information regarding the history and use of OCIPs in the design and construction of transportation projects. It will document the literature and the practice from both the owner and contractor perspectives. The consultant submitted the synthesis first draft, and the panel elected to conduct by-mail review. The second draft was forwarded to the 20-5 committee and the consultant submitted a revised final draft. This was approved by the SNO, and was sent to publication on 9/11/02, and published at the end of the year. Copies have been sent to Jack Basso at AASHTO.

There is a wide range of effort associated with preparing and approving design exceptions. In part, this is due to various project types or funding classifications, differing state laws governing tort liability and design immunity, and state DOT organizational structure. This synthesis will identify the various practices used by states. It will review the literature and survey state departments of transportation in order to summarize design exception practices, document the problems and measured benefits reported by the states, summarize the lessons learned (e.g., the frequency and outcome of using design exceptions in court cases), and identify potential streamlining efforts in the design exception process, as reported by the states. The first draft has been received, and the second panel meeting held November 25, 2002. The second draft was delivered, reviewed by the panel and 20-5 committee and the consultant will deliver the revised final draft in early April 2003.

This synthesis study will summarize the literature and survey transportation agencies and others to document the use of prefabricated bridge components and systems that minimize traffic disruption in the work zone while maintaining construction quality. It will focus on rehabilitation and replacement of commonly used bridges using the "Get in, Get out, and Stay out" philosophy. The study will include information on benefits of minimal traffic disruption (e.g., safety); quality issues (e.g., durability, connections); constructability (e.g., design considerations -- component sizes and weights, transport, and erection); and costs (e.g., user, construction, maintenance). The first draft has been received, and the second panel meeting held Nov. 6, 2002. The second draft was delivered 2/27/03 and was forwarded for panel and 20-5 review. The final draft was received in June 2003, and has been been forwarded for editing and SNO approval. The report was printed in December 2003, and was reprinted, due to poor quality reproduction of the figures.

Product evaluation programs exist in many states and are operating at different levels, ranging from well-developed and effective programs to programs that are in the developmental stages and/or partially functional. This synthesis will summarize state DOT practices for product evaluation, including program structure, evaluation procedures, and the implementation of the evaluation process results. Items to be considered, include, but are not limited to: product evaluation program organization, funding and procedures; types of products evaluated; product acceptance criteria; acceptance options; and product-approval implementation. A consultant has been selected, the contracting and start-up processes are complete. The Stage I deliverables, the workplan, outline, and questionnaire, have been reviewed and approved. The consultant agreed that 33-03 would be a pilot for a web-based survey method (along with a hard-copy backup). The questionnaire was distributed to TRB reps on July 3, 2002. The second panel meeting to review the first draft was held Feb 7, 2003. Second draft was delivered in May 2003. 20-5 and panel comments have been sent to the consultant, and the final draft was delivered 10/27/03, and is in editing. Ediiting found Excel tables with corrupted data and it took the author some time to correct these. SNO approval was received 4/20/04. Publication is expected in August 1, 2004.

Many states are beginning to consider vegetation management in project planning and design in order to achieve long-term sustainability. This synthesis collects information about this from the current literature and a survey of tate transportation agencies to document roadside vegetation management research and priorities. It includes information on policies and regulations, costs and benefits, methods of vegetation management, environmental impacts, implementation, revegetation, and effectiveness. The document has been published as NCHRP Synthesis 341.

This synthesis study will review and document quick clearance legislation and responder policies and practices regarding incident clearance for both urban and rural areas. Responders include transportation and public safety agencies, towing and recovery companies, and other public and private concerns. Relevant research, including cost-benefit analyses, will also be reviewed. Key areas to be addressed include, but are not limited to: legislation that requires moving vehicles involved in minor crashes; liability and tort law related to moving vehicles, cargo, or debris; legislation to limit liability for damages that may occur during quick clearance; public information and driver education efforts; benefit analyses related to quick clearance activities; impact of financial responsibility on decision-making at the scene; scope of training for all involved in the clearance of highway incidents; and institutional and programmatic activities to support quick clearance. The stage 1 deliverables (work plan, outline, and questionnaire) were submitted and reviewed, and the questionnaire was distributed to TRB reps on June 7, 2002. The I-95 Corridor Coalition has a project (by PB Farradyne) on" Quick Clearance & Move It Best Practices." They approached TRB and requested that the two projects share information. The staff and the project panel were supportive, and Walter Dunn and PB Farradyne have been cooperating on this. The first draft was received and the panel reviewed it at their meeting of 12/11/02. The second draft was delivered in mid February, 2003, and was reviewed bythe 20-5 Committee. The final draft was delivered in April 2003 and was sent for editing and SNO approval. Printed 8/23/03.

State DOTs and local agencies are responsible for carrying out a range of program development and delivery activities that advance the overall safety performance of the roadway system. This synthesis will document the literature and practices among state highway agencies and local governments, and expanded cooperation between them, to successfully plan and implement adequate safety countermeasures and programs. This will include but not be limited to: improvements to existing facilities and new roadway design; roadway safety audits; data collection policies, protocols, and processes; safety trade-offs; state and local government partnerships; examples of public safety and transportation agency cooperation and reporting; effective local work zone safety practices; training and communications; and gaps in resources and tools. The consultant delivered the first draft, and the panel review meeting was held January 30, 2003. The second draft was delivered, and fowarded for 20-5 review in mid-March 2003. The final draft was received in May 2003, and has SNO approval and is in editing. The topic panel has strongly recommended formatting this document to be a workbook, and printing an extra 5,000 copies for local government distribution. FHWA has agreed to fund this. There will be a color cover and tabs to reference the appendicdes.

This synthesis will document the state of the practice in safety management system programs or similar efforts. It will report on the following topics: structures; state and local agency interaction, including accountability; roles and responsibilities of participants; how states developed multi-disciplinary strategic safety plans; how states identify and prioritize/select projects; funding sources; case studies; and monitoring and measurement. The final document has been published as Synthesis 322..

State DOTs, consultants, contractors, and producers of highway materials find it challenging to attract and retain qualified individuals. This synthesis will review key literature sourcesand survey state transportation agencies to summarize reported experiences. Items of specific interest include organizational culture; compensation packages; educational reimbursement; training and recogition programs; professional development; and succession planning. The final document has been published as Synthesis 323.

State DOTs have established processes, with varying degrees of complexity, to manage their annual highway letting program and deliver projects of high quality. This synthesis will identify the processes currently used by state DOTs for highway letting program management. Items of particular interest are the breadth and variation of program management structures, how they deal with change, and how data is shared. This synthesis of practice may establish a foundation for information and data sharing to facilitate and accelerate improvements in DOT highway letting program management. The delivered the first draft for panel review and the review panel met March 27, 2003. The second draft was delivered in June 2003. 20-5 and panel comments have been received, and forwarded to the consultant. The final draft was due November 15, 2003. This was delivered Jan 15, 2004, and forwarded to editing. SNO approval was received on June 28. Publication is expected on August 30, 2004.

The erection of steel bridges poses many critical issues for owners. Because there is a great variety of practices being used today, there are often concerns with speed, safety, quality, delays, and claims related to the erection of steel bridges. This synthesis will examine and discuss practices for steel erection of I- and box-girder bridges, particularly curved, skewed, and staged structures. It will address critical issues that influence steel bridge erection and the practices for dealing with those issues. Key items to consider include, but are not limited to: impact of design and analysis practices on erection; methods used to predict erection deflections as a function of bridge type and complexity; shop assembly practices and alternative methods of assuring proper assembled geometry; sequencing of erection to ensure proper fit-up and to achieve desired girder profile/geometry; stability issues during all phases of bridge construction; field connection practices and their impact on final geometry; and owner requirements for erection procedures, implementation of requirements, and impact of procedures on the quality of the erection. The consultant has delivered the first draft, and the panel review meeting was held January 13, 2003. The consultant delivered a second draft, mid-March 2003. This was been returned to him for further work before external review. After discussions with the consultant, it was decided to employ Dennis Mertz of U Delaware to assist as a co-author. Funds to pay Dr. Mertz will come from the $25,000 original contract. The panel has been notified of this decision. The revised 2nd draft is was delivered by Dr. Mertz in December 2003. Fred Beckman and Dr. Mertz have collaboratively revised the draft, which was received March 29, 2004, and was forwarded to the panel for their review. Review comments were sent to the consultants on May 28; the revised second draft was delivered and reviewed by panel and 20-5 committee. The consultants have prepared the final draft, which was submitted for SNO approval on November 16, and was published in May, 2005.

ISTEA directed the transportation planning, development, and implementation process from 1991 to 1997, requiring consideration of access to federal lands. Tourism and recreation were to be addressed by MPOs and states. TEA 21 continues in this direction. This synthesis will document how MPOs and states use different methods to incorporate tourist, visitor and recreation travel needs into the planning and decision-making process. Topics to be explored include technical analysis tools, institutional relationships/partnerships, innovative financing, and stakeholder involvement techniques. The final document has been published as synthesis 329.

Freight transportation has been growing and an ongoing challenge is the accommodation of new and existing freight transportation facilities. Issues have led to concerns. Resolution of these can be in conflict with economic growth and development objectives. This synthesis will identify successful effots in location and operations of freight transportation facilities and synthesize information on techniques and procedures required for such facilities to be "good neighbors". Topics to be addressed include traffic, safety, security, land use, and environmental issues. The final document has been published as Synthesis 320.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 339: Centerline Rumble Strips (CLRS) examines current design, installation, configuration, dimension, and visibility issues associated with CLRS.  The report addresses the need for guidance on warrants, benefits, successful practices, and concerns such as external noise and the reduced visibility of centerline striping material.  Also addressed are pavement deterioration, ice buildup in the grooves, adverse impact on emergency vehicles, and the effect of CLRS on bicyclists.  Particular attention was paid to available before-and-after CLRS installation crash data to document the safety aspects of CLRS and the availability of policies, guidelines, warrants, and costs regarding their use and design.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4860

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 336: Road Safety Audits examines the state of the practice of road safety audit (RSA) and road safety audit review applications for U.S. states and Canadian provinces. This synthesis also reviews international RSA practices.  RSAs were first introduced in the United Kingdom more than 20 years ago and have been applied in New Zealand and Australia since the 1990s.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4477

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 326: Strategic Planning and Decision Making in State Departments of Transportation examines state and provincial transportation departments' experience with strategic planning and synthesizes current approaches to linking strategic planning with other decision-making processes, including operational and tactical planning, resource allocation, performance management, and performance measurement.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=3673

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 334: Automated Pavement Distress Collection Techniques examines highway community practice and research and development efforts in the automated collection and processing of pavement condition data techniques typically used in network-level pavement management.  The scope of the study covered all phases of automated pavement data collection and processing for pavement surface distress, pavement ride quality, rut-depth measurements, and joint-faulting measurements. Included in the scope were technologies employed, contracting issues, quality assurance, costs and benefits of automated techniques, monitoring frequencies and sampling protocols in use, degree of adoption of national standards for data collection, and contrast between the state of the art and the state of the practice.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4370

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 334: Automated Pavement Distress Collection Techniques examines highway community practice and research and development efforts in the automated collection and processing of pavement condition data techniques typically used in network-level pavement management.  The scope of the study covered all phases of automated pavement data collection and processing for pavement surface distress, pavement ride quality, rut-depth measurements, and joint-faulting measurements. Included in the scope were technologies employed, contracting issues, quality assurance, costs and benefits of automated techniques, monitoring frequencies and sampling protocols in use, degree of adoption of national standards for data collection, and contrast between the state of the art and the state of the practice.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4370

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 340: Convertible Roadways and Lanes examines the characteristics and operational requirements, costs, and benefits of convertible roadways and lanes.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4660

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 337: Cooperative Agreements for Corridor Management examines the current state of practice in developing and implementing cooperative agreements for corridor management, elements of such agreements, and successful practices or lessons learned. The report focuses on cooperative agreements between two or more government agencies or between public and private entities that address land use and transportation linkages.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4659

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 338: Thin and Ultra-Thin Whitetopping summarizes available information to document how state departments of transportation and others are currently using thin and ultra-thin whitetopping overlays among various pavement rehabilitation alternatives. The report covers all stages of the proper application of whitetopping overlays, including project selection, design, materials selection, construction, maintenance, and eventual rehabilitation or replacement.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4630

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 333: Concrete Bridge Deck Performance examines previous and current design and construction practices designed to improve the performance of bridge decks. Topics covered in this synthesis include factors that contribute to the durability of concrete bridge decks; performance of various types of deck protection strategies; lessons learned and the current state of the practice in design, construction, and maintenance of concrete bridge decks; available comparative analysis of the effects of using different methods and materials; specific reports of successes and failures; sample design and construction specifications; and more.   This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4369

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 344: Winter Highway Operations examines changes that occurred between 1994 and 2004 to practices and strategies used to control the impacts of winter weather on the safe and efficient movement of traffic.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=5076

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 335: Pavement Management Applications Using Geographic Information Systems examines the state of the practice and knowledge of pavement management systems (PMS) using geographic information systems (GIS) and other spatial technologies, and discusses how the technologies have been combined to enhance the highway management process. The synthesis reviews the principal issues related to PMS data collection, integration, management, and dissemination; applications of spatial technologies for map generation and PMS spatial analysis; and implementation-related issues, including approaches used for integrating PMS and GIS and the different tools used to support pavement management decisions.  The final report is publshed at http://www.trb.org/news/blurb_detail.asp?id=4476

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 332: Access Management on Crossroads in the Vicinity of Interchanges examines current practices relating to access location and design on crossroads in the vicinity of interchanges. It identifies standards and strategies used on new interchanges and on the retrofit of existing interchanges.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4201

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 346: State Construction Quality Assurance Programs examines current quality assurance practices of state and federal departments of transportation with regard to highway materials and construction. The report focuses on the strategies and practices used by agencies to ensure quality.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=5150

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 342: Chip Seal Best Practices examines ways to assist in the development and implementation of pavement preservation programs by identifying the benefits of using chip seal as part of a preventive maintenance program and by highlighting advanced chip seal programs in use around the world.  The report includes approximately 40 best practices in the areas of chip seal design methods, contract administration, equipment practices, construction practices, and performance measures.  According to the report, the increased use of chip seals for maintenance can be a successful, cost-effective way of using preventive maintenance to preserve both low-volume and higher-volume pavements.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=4901

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 350: Crash Records Systems examines crash records systems practices and programs as applied to highway and traffic safety.  The report covers crash data collection, crash processing and management, and data linkages for reporting and analysis.  While no single comprehensive system examples are identified in the report, many examples of one or more successful components were found to address the needs of three groups of stakeholders—data collectors, data managers, and data users.  The report also contains information about lessons learned from examples of successful systems, addressing the needs and concerns of stakeholders.  This topis is published at http://www.trb.org/news/blurb_detail.asp?id=5840

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 352: Value Engineering Applications in Transportation examines the current value engineering (VE) practices of highway transportation agencies in the United States and Canada.  Value engineering (VE) is the systematic review of a project, product, or process to improve performance, quality, and/or life-cycle cost by an independent multidisciplinary team of specialists. The report identifies the reported best practices, key strengths, and challenges of current VE study processes and agency programs, and offers guidance on applying and improving the effectiveness of VE in projects and programs.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=5705

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 349: Developing Transportation Agency Leaders examines practices and innovative approaches that address the development of transportation leadership in today’s work environment.  The report covers demographics, recruitment and retention, leadership training, and succession management.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=5402

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 351 examines issues involved in acquiring access rights along roadways other than freeways. The report documents the state of the practice with the intent to limit the amount of access to the roadway for the purpose of managing highway safety and mobility.  The report documents successful practices and current policies, legal and real estate literature, and other publications that address this subject.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=5618

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 353: Inspection and Maintenance of Bridge Stay Cable Systems identifies and explains various inspection and maintenance techniques for bridge stay cable systems. It discusses both short- and long-term approaches. The report information on  methods for inspections and assessments, including nondestructive testing and evaluation procedures; repair and retrofit; methods for control of cable vibrations, including rain–wind vibrations; stay cable fatigue and failure; effectiveness of various inspection and repair methods; limitations of available technologies; and trends and recommendations for future study.  This topic is published at  http://www.trb.org/news/blurb_detail.asp?id=5841

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 354: Inspection and Management of Bridges with Fracture-Critical Details explores the inspection and maintenance of bridges with fracture-critical members (FCMs), as defined in the American Association of State Highway and Transportation Officials’ Load and Resistance Factor Design (LRFD) Bridge Design Specifications.  The report identifies gaps in literature related to the subject; determines practices and problems with how bridge owners define, identify, document, inspect, and manage bridges with fracture-critical details; and identifies specific research needs. Among the areas examined in the report are inspection frequencies and procedures; methods for calculating remaining fatigue life; qualification, availability, and training of inspectors; cost of inspection programs; instances where inspection programs prevented failures; retrofit techniques; fabrication methods and inspections; and experience with fracture-critical members fractures and problems details.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=5870

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 347: Managing Archaeological Investigations addresses practices that improve archaeological investigations by both streamlining the overall transportation project delivery process and enhancing the stewardship of archaeological resources. The report examines practices that improve and maintain good communication and coordination at all stages of transportation programs, including that between agencies and Native Americans and efforts at public outreach. It also reviews internal state department of transportation (DOT) business practices, and examines effective and innovative practices for complying with Section 106 of the National Historic Preservation Act, the National Environmental Policy Act, and project design. The synthesis also examines pre-project planning efforts, including programmatic agreements, treatment guidance and specifications on specific archaeological resources, creative mitigation, and effective collection methods.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=5275

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 348: Improving the Safety of Older Road Users examines programs and policies in place across the country to improve the safety and mobility of older road users. The report documents a range of strategies and related programs under way in roadway engineering, driver licensing, public information and education, and enforcement and adjudication.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=5479

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 327: Transportation Implications of Emerging Economic Development Trends explores economic development trends and how transportation relates to these trends.  The report focuses on business production, inventory, and logistics and distribution trends and practices; site selection research and practices; labor market considerations; urban and rural development practices; and international trade and global market trends and implications.  The final report is at http://www.trb.org/news/blurb_detail.asp?id=9443

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 355: Transportation Technology Transfer: Successes, Challenges, and Needs explores the use of technology transfer practices in the highway transportation community. The report documents successful practices, discusses challenges encountered, and identifies the needs of those responsible for sponsoring, facilitating, and conducting technology transfer activities and processes.  This final report is pubilshed at http://www.trb.org/news/blurb_detail.asp?id=5977

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 359: Bridge Rating Practices and Policies for Overweight Vehicles explores overweight vehicle permit processes.  The report includes information on state and provincial bridge rating systems, bridge evaluation practices, and permit policies as they relate to overweight and oversize vehicles.  The report is designed to help in the understanding of the reasons for nonuniform permitting practices.  The report reviews specifications, software types, treatment of nonstandard configurations, and allowance for in-place dead loads; processes of permit review; and personnel assigned to permit review.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=6516

TRB’s National Cooperative Highway Research Program (NCHRP) Report 396: Monitoring Scour Critical Bridges explores the current state of practice for fixed scour bridge monitoring.

 

TRB’s National Cooperative Highway Research Program (NCHRP) Syntheses 367: Technologies for Improving Safety Data explores new technologies for the acquisition, processing, and overall management of crash, roadway inventory, and traffic operations data.  The report examines the current state-of-the-practice and state-of-the-art use of technologies for efficient and effective collection and maintenance of data for highway safety analysis.  The final report is at  http://www.trb.org/news/blurb_detail.asp?id=8042

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 361: Visualization for Project Development explores the visual representation of proposed alternatives and improvements and their associated effects on the existing surroundings.  The report examines the best practices and experiences within transportation agencies that are developing and incorporating visualization into the project development process.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=6911

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 363: Control of Invasive Species explores the extent to which state departments of transportation are identifying actions that affect the spread of invasive species, preventing introduction, tracking status and locations of “invasives” in a timely and ongoing manner, controlling found populations, restoring invaded habitats, conducting research, and sharing lessons learned.  The report documents successful practices and lessons learned.  It also synthesizes the state of the practice in developing Integrated (Roadside) Vegetation Management, along with physical, chemical, biological, and cultural control mechanisms.  The final report is at http://www.trb.org/news/blurb_detail.asp?id=7305

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 356: Pavement Markings—Design and Typical Layout Details identifies variations in pavement marking designs, practices, and policies, as provided by 48 of 50 state departments of transportation, and transportation agencies from the District of Columbia, Puerto Rico and four cities.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=6322

A synthesis is needed to report on state DOT transportation training, education, and professional development programs in order to provide valuable state of the practice input to the development of better workforce development programs. After review/comment at an August 2005 topic panel meeting and attending a state DOT training adminisrators' meeting, the consultant prepared a final draft that was sent out to the topic panel and 20-05 oversight committee for review/comment. Accommodating review comments, a final revised draft was submitted and has been published as NCHRP Synthesis 362.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 357: Use of Geophysics for Transportation Projects examines the state of the practice regarding the use of geophysics for transportation projects.  The report focuses on who is using geophysics and why, which methods and applications are the most commonly used, the use of in-house expertise compared with contracting private consultants, and how geophysical service contracts are procured and implemented.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=6259

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 358: Statewide Travel Forecasting Models examines statewide travel forecasting models designed to address planning needs and provide forecasts for statewide transportation, including passenger vehicle and freight movements.  The report explores the types and purposes of models being used, integration of state and urban models, data requirements, computer needs, resources (including time, funding, training, and staff), limitations, and overall benefits. The report includes five case studies, two that focus on passenger components, two on freight components, and one on both passenger and freight.   This topic is published at http://www.trb.org/news/blurb_detail.asp?id=6571

This synthesis was to report on the closing of intermodal truck-rail freight terminals across the U.S. Communication and planning processes that were implemented before, during, and after the closures will be documented and successful practice in mitigating the impacts resulting from the eventual mode shifts from rail to truck will also be investigated. State DOTs, local MPOs, and regional economic development authorities may be contacted for information. The topic experienced repeated adminstrative problems. As it is now out of phase with the rest of the 36-00 topics, it has been withdrawn, with the concurrence of the 20-05 oversight committee.  

TRB’s National Cooperative Highway Research Program (NCHRP) Syntheses 364: Estimating Toll Road Demand and Revenue examines the state of the practice for forecasting demand and revenues for toll roads in the United States.  The report explores the models that are used to forecast the demand for travel and the application of these models to project revenues as a function of demand estimates.  The final report is at  http://www.trb.org/news/blurb_detail.asp?id=7570

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 360: Rock-Socketed Shafts for Highway Structure Foundations explores current practices pertaining to each step of the design process, along with the limitations; identifies emerging and promising technologies; examines the principal challenges in advancing the state of the practice; and investigates future developments and potential improvements in the use and design of rock-socketed shafts.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=6678

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 366: Tribal Transportation Programs explores innovations and model practices among tribal transportation programs. The report also examines the history, and legal and administrative evolution, of tribal transportation programs within the larger context of issues of tribal sovereignty and relationships with federal, state, and local governments, and local and regional planning agencies.  The final report is available at http://www.trb.org/news/blurb_detail.asp?id=7746

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 373: Multi-Disciplinary Teams in Context-Sensitive Solutions explores inclusion of multiple perspectives and disciplines in the decision-making process associated with developing transportation solutions that improve the quality of life for the communities being served by transportation agencies. A copy of this report can be found at http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_syn_373.pdf

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 365: Preserving and Using Institutional Memory through Knowledge Management Practices explores practices regarding the preservation and use of institutional memory through the knowledge management practices of United States and Canadian transportation agencies. The report examines practices for the effective organization, management, and transmission of materials, knowledge, and resources that are in the unique possession of individual offices and employees.  This topic is published at http://www.trb.org/news/blurb_detail.asp?id=7401

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 371: Managing Selected Transportation Assets: Signals, Lighting, Signs, Pavement Markings, Culverts, and Sidewalks explores the state of the practice for managing transportation infrastructure assets other than pavements and bridges, and documents gaps in knowledge and areas in need of potential further study.  The link to the final report is http://trb.org/news/blurb_detail.asp?id=8496

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 375: Bridge Inspection Practices examines bridge inspection practices in the United States and selected foreign countries.  The report explores inspection personnel (staff titles and functions, qualifications, training and certification, inspection teams, and the assignment of teams to bridges), inspection types (focus, methods, and frequency), and inspection quality control and quality assurance.  The report also reviews the uses agencies make of information gathered from bridge inspections, what triggers repairs, and plans for future development of inspection programs.  The final report is at

http://trb.org/news/blurb_detail.asp?id=8829

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 372: Emerging Technologies for Construction Delivery explores the use of five emerging technologies for transportation construction projects: global positioning systems for layout, machine guidance, and quantity tracking; handheld computers for construction records; automated temperature tracking for concrete maturity monitoring; four-dimensional computer-aided drafting modeling for constructability analysis and improved communications; and web-based video cameras for remote project monitoring.  The final report is at http://trb.org/news/blurb_detail.asp?id=8659

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 397: Bridge Manangement Systems for Transportation Agency Decision Making explores how bridge management systems are employed by transportation agencies in making network-level decisions on resource allocations for their bridge programs.  The report has been published http://www.trb.org/Publications/Blurbs/Bridge_Management_Systems_for_Transportation_Agenc_162050.aspx.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 369: State DOT Crash Reconstruction Practices examines the extent of crash reconstruction undertaken by state departments of transportation (DOTs) and the level of expertise available to perform the tasks.  In addition, the report explores the extent to which crash reconstructions are used by state DOTs to improve highway safety.  The final report is published at http://www.trb.org/news/blurb_detail.asp?id=7973

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 389: Performance-Based Contracting for Maintenance explores experience with performance-based maintenance contracting in places where it has been adopted, including such issues as whether it has the potential to reduce costs and improve maintenance levels of service. The final report is available at http://www.trb.org/news/blurb_detail.asp?id=10491

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 374: Preserving Freight and Passenger Rail Corridors and Service explores issues associated with the retention of railroad rights-of-way or restoration of rail services. The report can be found at http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_syn_374.pdf

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 395: Debt Finance Practices for Surface Transportation examines basic principles of debt issuance for public agencies. The report explores issues that may be useful in assisting in decisions on when and how to best use debt financing techniques to fund investments in transportation infrastructure. The final report is available at http://www.trb.org/news/blurb_detail.asp?id=10301

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 370: Animal-Vehicle Collision Data Collection examines the extent to which data from animal–vehicle collision accident reports and animal carcass counts are collected, analyzed, and used throughout the United States and Canada.  The final report is at http://www.trb.org/news/blurb_detail.asp?id=8422

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 368: Cone Penetrating Testing explores the current practices of departments of transportation associated with cone penetration testing (CPT).  The report examines cone penetrometer equipment options; field testing procedures; CPT data presentation and geostratigraphic profiling; CPT evaluation of soil engineering parameters and properties; CPT for deep foundations, pilings, shallow foundations, and embankments; and CPT use in ground modifications and difficult ground conditions.  The final report is published at  http://www.trb.org/news/blurb_detail.asp?id=8306

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 376: Quality Assurance in Design-Build Projects examines how state transportation agencies have successfully approached quality assurance for design-build, including in procurement, design, construction, and post-construction operations and maintenance.  The report is published at  http://www.trb.org/news/blurb_detail.asp?id=9318

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 377: Compilation of Public Opinion Data on Tolls and Road Pricing explores how the public feels about tolls and road pricing, examines public opinion concerning charging for the use of roads, and highlights factors associated with the acceptance or rejection of road pricing. This topic is published at http://www.trb.org/news/blurb_detail.asp?id=9125

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 388: Pre-Overlay Treatment of Existing Pavements explores current pre-overlay treatment practices of state departments of transportation for both hot-mix asphalt and portland cement concrete pavement structures.  The report is designed to help pavement management and pavement design groups in their selection of pre-overlay treatments. The final report is available at http://www.trb.org/news/blurb_detail.asp?id=10051

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 384: Forecasting Metropolitan Commercial and Freight Travel explores methods of freight and commercial vehicle forecasting currently in professional practice, along with promising methods emerging from ongoing research.  The primary focus of the report is on metropolitan-level forecasting, although some consideration is given to statewide freight models.  Report located at http://www.trb.org/news/blurb_detail.asp?id=9871.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 386: High-Speed Weigh-in-Motion System Calibration Practices explores the state of the practice in high-speed weigh-in-motion system calibration.  Weigh-in-motion is the process of weighing vehicle tires or axles at normal roadway speeds ranging up to 130 km/h (80 mph).  The final report is available at http://www.trb.org/news/blurb_detail.asp?id=9955

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 383: Changeable Message Sign (CMS) Displays During Non-Incident, Non-Roadwork Periods explores the use of CMSs to convey messages on non-recurrent, environmental, special event traffic, and other special problems.  Report located at http://www.trb.org/news/blurb_detail.asp?id=9710.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 379: Selection and Evaluation of Alternative Contracting Methods to Accelerate Project Completion explores the process for selection of alternative contracting methods that can potentially accelerate project completion.  The report also examines factors associated with selecting one type of alternative contracting technique over another.  The report is available at http://www.trb.org/news/blurb_detail.asp?id=9552

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 380: Applications of Illuminated, Active, In-Pavement Marker Systems (IPMs) explores the state of IPM technology, experiences with IPM applications, and potential IPM research needs.  The final report can be found at http://www.trb.org/news/blurb_detail.asp?id=9578

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 401: Quality Management of Pavement Condition Data Collection explores the quality management practices being employed by public highway agencies for automated, semi-automated, and manual pavement data collection and delivery.

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digests 339: Improving the Safety of Mobile Lane Closures explores practices employed by transportation agencies during mobile lane closures and summarizes research carried out on different components of mobile lane closure. 

Appendices A through D for NCHRP RRD 339 are available online.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 398: Cathodic Protection for Life Extension of Existing Reinforced Concrete Bridge Elements examines the use of cathodic protection by state transportation agencies for controlling corrosion on existing reinforced concrete bridge elements. The report also explores the different types of cathodic protection systems, highlights case studies of states using these systems, and reviews reasons why public agencies may or may not employ cathodic protection.

Appendix A: Summaries of Questionnaires and Interview Results is available online.
Project: Project Information

This report is published http://www.trb.org/Publications/Blurbs/Cathodic_Protection_for_Life_Extension_of_Existing_162284.aspx

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 390: Performance-Based Construction Contractor Prequalification explores experiences and practices of state transportation agencies associated with performance-based construction contractor prequalification.  The report also examines information on the process developed in other sectors of the construction industry. This report is located at http://www.trb.org/news/blurb_detail.asp?id=10081

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 392: Transportation’s Role in Emergency Evacuation and Reentry explores information on transportation’s role in emergency evacuation and reentry by summarizing aspects of its planning, control, and research as well as highlighting effective and innovative practices.This report is located at http://www.trb.org/news/blurb_detail.asp?id=10106

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 391: Public Sector Decision Making for Public–Private Partnerships examines information designed to evaluate the benefits and risks associated with allowing the private sector to have a greater role in financing and developing highway infrastructure.  This report is located at http://www.trb.org/news/blurb_detail.asp?id=10079

The st   TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 394: Reducing Liter on Roadsides explores the state of the practice in reducing roadside litter as it involves state departments of transportation (DOTs). The report provides information concerning the prevention and removal of roadside litter, unfulfilled needs, knowledge gaps, and underperforming activities. It covers enforcement, education, awareness, and engineering methods for both litter prevention and collection. This report is located at http://www.trb.org/news/blurb_detail.asp?id=10562

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 399: Real-Time Traveler Information Systems explores the needs and expectations of travelers, the current status of a variety of traveler information systems in the United States, available and emerging data sources, and business models for sustaining traveler information. This report is located at http://www.trb.org/news/blurb_detail.asp?id=10633

 TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 337: Design Flexibility Considerations for Built Urban Environments explores issues related to the use of roadway design exceptions or variances.  The report also examines processes designed to help manage the use of exceptions or variances, and highlights potential means to provide a timely procedure for addressing design exceptions or variances. This report is located at http://www.trb.org/news/blurb_detail.asp?id=10263

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 393: Adjacent Precast Concrete Box Beam Bridges: Connection Details explores current design and construction practices that are reported to reduce the likelihood of longitudinal cracking in box beam bridges. This report is located at http://www.trb.org/news/blurb_detail.asp?id=10217

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 423: Long-Term Performance of Polymer Concrete for Bridge Decks addresses a number of topics related to thin polymer overlays (TPOs).

Those topics include previous research, specifications, and procedures on TPOs; performance of TPOs based on field applications; the primary factors that influence TPO performance; current construction guidelines for TPOs related to surface preparation, mixing and placement, consolidation, finishing, and curing; repair procedures; factors that influence the performance of overlays, including life-cycle cost, benefits and costs, bridge deck condition, service life extension, and performance; and successes and failures of TPOs, including reasons for both.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 400: New Approaches to Ecological Surveys explores ecological survey needs related to transportation activities and examines technologies, techniques, and innovative methods to fulfill those needs.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 435: Recycled Materials and Byproducts in Highway Applications—Summary Report, Volume 1 summarizes the results of a project that describes the experiences of transportation agencies in determining the relevant properties of recycled materials and industrial byproducts and the beneficial use for highway applications.

NCHRP Synthesis 435 is presented in eight volumes and is designed to help serve as a guide to states revising the provisions of their materials specifications to incorporate the use of recycled materials and industrial byproducts.

Volume 1 is available in print and electronic versions. Volumes 2 to 8 are in electronic format only. The eight volumes are:
Volume 1 Recycled Materials and Byproducts in Highway Applications—Summary Report
Volume 2 Coal Combustion Byproducts
Volume 3 Non-Coal Combustion Byproducts
Volume 4 Mineral and Quarry Byproducts
Volume 5 Slag Byproducts
Volume 6 Reclaimed Asphalt Pavement, Recycled Concrete Aggregate, and Construction Demolition Waste
Volume 7 Scrap Tire Byproducts
Volume 8 Manufacturing and Construction Byproducts

A NCHRP Synthesis 435 website with links to all 8 volumes is available.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 402: Construction Manager-at-Risk Project Delivery for Highway Programs explores current methods in which state departments of transportation and other public engineering agencies are applying construction manager-at-risk (CMR) project delivery to their construction projects.

CMR project delivery is an integrated team approach to the planning, design, and construction of a highway project, to help control schedule and budget, and to help ensure quality for the project owner. The team consists of the owner; the designer, who might be an in-house engineer; and the at-risk construction manager. The goal of this project delivery method is to engage at-risk construction expertise early in the design process to enhance constructability, manage risk, and facilitate concurrent execution of design and construction without the owner relinquishing control over the details of design as it would in a design-build project.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 403: Adaptive Traffic Control Systems: Domestic and Foreign State of Practice explores the state of practice of adaptive traffic control systems (ATCSs), also known as real-time traffic control systems, which adjust, in real time, signal timings based on traffic conditions, demand, and system capacity.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 405: Utility Location and Highway Design explores current practices in use by transportation agencies for consideration of utilities during the project development process, including where in the process the utility impacts are assessed and relocation decisions made; what policies, regulations, manuals, and guidelines are used; and how design decisions are influenced by utilities.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 407: Effective Public Involvement Using Limited Resources explores information about staff and agency experiences in the application of successful and cost-effective strategies and implementation techniques used to engage the public in the development of transportation plans and projects. The report also examines unsuccessful strategies.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 406: Advanced Practices in Travel Forecasting explores the use of travel modeling and forecasting tools that could represent a significant advance over the current state of practice. The report examines five types of models: activity-based demand, dynamic network, land use, freight, and statewide.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 422: Trade-Off Considerations in Highway Geometric Design describes the processes that transportation agencies currently use to evaluate geometric design trade-offs between competing interests.

The report also highlights existing key publications on conventional approaches, context-sensitive solutions/context-sensitive design, and performance-based approaches, as well as gaps in information or analysis processes available to support design decisions.

  

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 412: Speed Reduction Techniques for Rural High-to-Low Speed Transitions explores techniques for lowering traffic speeds in rural transition zones. Transition zones are those portions of high-speed roads that have lower posted speed limits as the roadway approaches a settlement.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 410: Freight Transportation Surveys profiles the state of the practice in methods and techniques used to survey and collect data on freight transportation. The report also examines issues, identifies gaps in knowledge, and notes areas for potential future research in the area of freight transportation systems.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 409: Traffic Signal Retiming Practices in the United States explores practices that operating agencies currently use to revise traffic signal timing. The report examines the processes used to develop, install, verify, fine-tune, and evaluate the plans.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 404: TRB’s State of the Practice in Highway Access Management examines current practice, potential barriers, and possible enhancements to highway access management programs. The report focuses on legal, legislative, policy, program, implementation, and effectiveness issues related to access management.

Appendixes A-D of NCHRP Synthesis 404 are available online. 

• Appendix A Access Management Survey
• Appendix B List of Responding Agencies
• Appendix C Summary of Survey Responses
• Appendix D Retrofit Toolbox

 

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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 421: Recycling and Reclamation of Asphalt Pavements Using In-Place Methods discusses the use of hot in-place recycling, cold in-place recycling, and full-depth reclamation of asphalt pavements.

In-place recycling and reclamation of asphalt pavements provides agencies with the ability to optimize the value of in-place materials, minimize construction time and traffic flow disruptions, and reduce the number of construction vehicles moving in and out of the construction area.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 417: Geometric Design Practices for Resurfacing, Restoration, and Rehabilitation documents the current state-of-the-practice related to nonfreeway resurfacing, restoration, and rehabilitation projects.

Appendix G, Summary of Good Practices: Incorporating Safety into Resurfacing and Restoration Projects, to NCHRP Synthesis 417 is only available as part of the electronic version of the report.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 414: Effective Delivery of Small-Scale Federal-Aid Projects examines streamlined methods for meeting federal funding requirements for small-scale highway projects.

The report explores ways that state departments of transportation work with local agencies to implement small projects eligible for federal funding.

Appendix G to NCHRP Synthesis 414 is available only in the pdf version of the report.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 424: Engineering Economic Analysis Practices for Highway Investment explores how U.S. transportation agencies have applied engineering economics--benefit–cost analyses and similar procedures--to decisions on highway investments.

    TRB Publication Type: NCHRP Research Results Digest

TRB’s National Cooperative Highway Research Program (NCHRP) 415: Design Fires in Road Tunnels information on the state of the practice of design fires in road tunnels, focusing on tunnel fire dynamics and the means of fire management for design guidance.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 461: Accelerating Implementation of Transportation Research Results examines implementation practices used by public-sector nontransportation agencies, nonprofits, and academia to accelerate practical application of research results. The emphasis is on practices that might be useful for transportation agencies to create more responsive research programs.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 420: Operational and Institutional Agreements That Facilitate Regional Traffic Signal Operations (RTSOPs) identifies and highlights critical attributes of successful RTSOPs across the United States.

Regions can use RTSOPs to help improve traffic flow as it crosses from one jurisdiction to another. A central focus of these programs is the coordination of signal timing on multi-jurisdictional arterials; however, RTSOPs can also facilitate the consideration of other traffic operations measures to improve regional mobility.

Many RTSOPs have been established through regional metropolitan planning organizations, and successful RTSOPs also have been established by other organizations, including state and local departments of transportation and government corporations.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 416: Implementing Race-Neutral Measures in State Disadvantaged Business Enterprise Programs explores race-neutral strategies being used effectively by state departments of transportation (DOTs) to meet their Disadvantaged Business Enterprises (DBE) participation goals. It also reviews and synthesizes problems faced by state DOTs in the administration of their DBE programs and identifies race-neutral remedies used to overcome these challenges.

As state DOT's carry out their highway construction programs, they are required to direct a portion of their federal-aid fund expenditures toward small businesses called DBEs. A DBE is defined as a small, for-profit business concern that is at least 51% owned and controlled by one or more socially and economically disadvantaged individuals. States are required to meet the maximum feasible portion of their DBE participation goals using race-neutral means designed to remove barriers and enhance opportunities for all small businesses, not just DBEs.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 413: Techniques for Effective Highway Construction Projects in Congested Urban Areas explores a diverse set of techniques designed to address highway construction challenges in congested urban areas such as high-traffic volumes, utility conflicts, complex right-of-way acquisition issues, a diverse stakeholder base, and watchful news media.

The report includes four case studies designed to help illustrate effective construction practices in congested urban areas.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 418: Developing Production Pile Driving Criteria from Test Pile Data provides information on the current practices used by state transportation agencies to develop pile driving criteria, with special attention paid to the use of test pile data in the process.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 419: Transportation Improvement Program Revision Process compiles and documents the different ways that metropolitan planning organizations (MPOs) approach revising a Transportation Improvement Program (TIP) once it has been adopted.

Federal legislation requires MPOs to adopt and regularly update a TIP identifying a prioritized list of projects covering a four-year period.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 429: Geotechnical Information Practices in Design-Build Projects addresses how states use geotechnical information in solicitation documents and contracts for design-build highway projects.

The report examines current practices regarding the allocation of geotechnical risk and the level of geotechnical information provided with bid documents, the scope of geotechnical information required after contract award, geotechnical-related performance testing during construction, and contract provisions related to geotechnical design and construction.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 434: Use of the U.S. Census Bureau’s Public Use Microdata Sample (PUMS) by State Departments of Transportation and Metropolitan Planning Organizations describes ways that transportation planners are using the PUMS data.

The report is designed to serve as a reference for transportation planners who may be able to exploit these data. Census microdata are the confidential records of specific individuals and housing units from whom Decennial Census or American Community Survey responses have been obtained.

The U.S. Census Bureau also draws a sample from the full set of microdata and makes these sampled records available in the PUMS data products, so that users can develop their own tabulations.

These data are being used by state departments of transportation and metropolitan planning organizations for studies, such as analyses of the commuting characteristics of population subgroups, and for supporting travel demand model and land use models.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 428: Practices and Procedures for Site-Specific Evaluations of Earthquake Ground Motions identifies and describes current practice and available methods for evaluating the influence of local ground conditions on earthquake design ground motions on a site-specific basis.

The report focuses on evaluating the response of soil deposits to strong ground shaking.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 432: Recent Roadway Geometric Design Research for Improved Safety and Operations reviews and summarizes roadway geometric design literature completed and published from 2001 through early 2011, particularly research that identified impacts on safety and operations.

The report is structured to correspond to chapters in the American Association of State Highway and Transportation Officials’ A Policy on Geometric Design of Highways and Streets, more commonly referred to as the Green Book.

NCHRP Synthesis 432 is an update of NCHRP Synthesis 299 on the same topic published in 2001.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 437: Assessing the Long-Term Performance of Mechanically Stabilized Earth Walls explores methods to assess the long-term performance of mechanically stabilized earth walls. For the purposes of the report, "long-term" denotes the period of time from approximately one year after the wall is in service until the end of its design life.

The report focuses on state and federal agency wall inventories and highlights methods of inspection and assessment of wall conditions.

Mechanically stabilized earth walls are retaining walls that rely on internal reinforcement embedded in the backfill for stability.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 426: Performance-Based Highway Maintenance and Operations Management explores performance-based management practices that are applied by state departments of transportation (DOTs) in highway maintenance and operations.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 425: Waterproofing Membranes for Concrete Bridge Decks documents information on materials, specification requirements, design details, application methods, system performance, and costs of waterproofing membranes used on new and existing bridge decks since 1995.

The synthesis focuses on North American practices with some information provided about systems used in Europe and Asia.

NCHRP Synthesis 425 is an update to NCHRP Synthesis 220: Waterproofing Membranes for Concrete Bridge Decks that was published in 1995.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 430: Cost-Effective and Sustainable Road Slope Stabilization and Erosion Control presents information on cost-effective and sustainable road slope stabilization techniques, with a focus on shallow or near-surface slope stabilization and related erosion control methods used on low-volume roads.

The report address topic planning, site investigation, erosion control techniques, soil bioengineering and biotechnical techniques, mechanical stabilization, and earthwork techniques.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 427: Extent of Highway Capacity Manual Use in Planning assesses how state departments of transportation, small and large metropolitan planning organizations, and local governments are using or might use the Highway Capacity Manual for planning analyses, or more specifically, for performance monitoring, problem identification, project prioritization, programming, and decision-making processes.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 436: Local Policies and Practices That Support Safe Pedestrian Environments documents various tools and strategies used by municipalities to improve the safety, convenience, and accessibility of the pedestrian experience.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 431: Practices to Manage Traffic Sign Retroreflectivity includes examples of practices that illustrate how different types of transportation agencies might meet federal retroreflectivity requirements for traffic signs.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 439: Use of Transportation Asset Management Principles in State Highway Agencies explores the state of practice for transportation asset management among state departments of transportation.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 441: High Performance Specifications and Practices for Bridges documents the types of specifications and practices used by state transportation agencies to produce high performance concrete for bridges. The report also identifies specifications and practices reported as having improved concrete performance and those that have been less successful.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 445: Practices for Unbound Aggregate Pavement Layers consolidates information on the state-of-the-art and state-of-the-practice of designing and constructing unbound aggregate pavement layers. The report summarizes effective practices related to material selection, design, and construction of unbound aggregate layers to potentially improve pavement performance and longevity.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 442: Practices and Performance Measures for Local Public Agency Federally Funded Highway Projects explores what performance measures, delivery practices, strategies, and tools are currently used in relation to federally-funded local public agency (LPA) highway project development and delivery, and how they are used to measure success in project administration.

Appendix D to NCHRP Synthesis 422, which provides samples of documents that exhibit practices or performance measures for federally funded LPA transportation projects, is not included in the print or PDF version of the report. Appendix D is available online.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 443: Practical Highway Design Solutions presents information on the application of practical design approaches in roadway project development.

Practical design is the default term used in the report to describe approaches or initiatives some state transportation agencies have adopted that result in design solutions for specific roadway projects believed to better address the critical needs of the entire roadway system.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 440, Performance-Based Seismic Bridge Design (PBSD) summarizes the current state of knowledge and practice for PBSD. PBSD is the process that links decision making for facility design with seismic input, facility response, and potential facility damage.

The goal of PBSD is to provide decision makers and stakeholders with data that will enable them to allocate resources for construction based on levels of desired seismic performance.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 438: Expedited Procurement Procedures for Emergency Construction Services explores procurement procedures being utilized by state departments of transportation in coordination with federal agencies to repair and reopen roadways in emergency situations.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 446: Use of Advance Geospatial Data, Tools, Technologies, and Information in Department of Transportation Projects that explores the development, documentation, and introduction of advanced geospatial technologies within departments of transportation.

The report also provides a discussion of strengths and weaknesses of leading technologies, and how they are being used today.

 

 

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 447: Active Traffic Management for Arterials practices associated with the design, implementation, and operation of active traffic management (ATM) on arterial roadways.

ATM includes a suite of strategies that are used to manage traffic flow in order enhance capacity and safety.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 438: Expedited Procurement Procedures for Emergency Construction Services explores procurement procedures being utilized by state departments of transportation in coordination with federal agencies to repair and reopen roadways in emergency situations.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 449: Strategies to Mitigate the Impacts of Chloride Roadway Deicers on the Natural Environment documents the range of methods, tools, and techniques used by transportation agencies to minimize the environmental impact of chloride-based roadway deicers.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 452: State Department of Transportation Fleet Replacement Management Practices explores the current state of the practice regarding fleet replacement management and financing methods by state departments of transportation. The report also includes a discussion of the perceived strengths and weaknesses of different management and financing methods.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 451: Emergency Medical Services Response to Motor Vehicle Crashes in Rural Areas identifies potential factors that may help reduce the time needed to provide effective medical care to crash occupants on rural roads.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 472: FEMA and FHWA Emergency Relief Funds Reimbursements to State Departments of Transportation documents the experiences of state departments of transportation (DOTs) with federal disaster reimbursement programs. The report summarizes efforts and enhancements made by DOTs to secure appropriate reimbursements and simplify cost identification.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 459: Using the Economic Value Created by Transportation to Fund Transportation presents information on financing mechanisms used by transportation agencies to capture a portion of the economic value created by public investment in transportation infrastructure to fund transportation improvements.

The report provides an overview of ten types of “value capture” mechanisms and presents case examples of how transportation agencies have used these mechanisms to help fund specific highway projects.

This topic is being canceled due to an overlap with existing research.   email: jwilliams@nas.edu      

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 463: Pavement Patching Practices summarizes current practices for patching small-scale surface defects in concrete and asphalt pavements.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 464: Thin Asphalt Concrete Overlays documents the current state of the practice as well as research efforts on the use of thin asphalt concrete overlays for pavement maintenance, rehabilitation, and preservation.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 455: Alternative Technical Concepts for Contract Delivery Methods Transportation documents various methods by which agencies have successfully implemented alternative technical concepts (ATCs) during the highway contracting process.

The report identifies methods that promote transparency and fairness, while at the same time protecting the industry’s right to confidentiality. The U.S. Federal Highway Administration defines an ATC as “a request by a proposer to modify a contract requirement, specifically for that proposer’s use in gaining competitive benefit during the bidding or proposal process … [and] must provide a solution that is equal to or better than the owner’s base design requirements in the invitation for bid or request for proposal document.”

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 456: Non-Nuclear Methods for Compaction Control of Unbound Materials documents information on national and international experience with non-nuclear devices and methods for measuring compaction of unbound materials.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 462: Managing Longitudinal Utility Installations on Controlled Access Highway Right-of-Way surveys state departments of transportation (DOTs) to identify and synthesize exemplary practices to help highway officials manage longitudinal utility installations on controlled access highway right-of-ways.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 468: Interactive Training for All-Hazards Emergency Planning, Preparation, and Response for Maintenance and Operations Field Personnel identify interactive emergency training tools and sources that may be applied by maintenance and operations field personnel of state departments of transportation and public works agencies. The report also identifies potential obstacles to their implementation and develops a toolkit of relevant training and exercise information.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 460: Sharing Operations Data Among Agencies document both the qualitative and quantitative business cases for sharing data among transportation-related agencies. The study also documents the institutional, legal, and technical challenges that can inhibit data sharing.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 465: Permanent Signs Mounted on Median Barriers reports on the current state of practice for mounting permanent highway signs on top of rigid median barriers throughout the United States.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 453: State Bridge Load Posting Processes and Practices is a synthesis of the practices of U.S. state governments in restricting weights of vehicles that can cross highway bridges and culverts to levels below legal loads. Bridges and culverts restricted for vehicle weights are called load posted structures. The load posting practices of bridge owners include the identification of structures to post for load, the evaluation of safe load capacities of these structures, and the implementation of restrictions on vehicle weights at structures.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 474: Service Life of Culverts explores the time during which a culvert is expected to provide a desired function with a specified level of maintenance established at the design or retrofit stage.

This study is an update of NCHRP Synthesis 254: Service Life of Drainage Pipe (1998), which itself was an update of NCHRP Synthesis 50: Durability of Drainage Pipe (1978). Developments in plastic pipe, fiber-reinforced concrete pipe, polymeric-coated metal pipe, recycled materials, larger and more diverse structures, and sophisticated analytical soil-structure interaction modeling within the past 15 years led to the development of this report.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 471: Practices for Developing Transparent Best Value Selection Procedures examines practices related to the best value bid approach to procuring highway construction services. Best value procurement is a process to select the most advantageous offer by evaluating schedule, technical merit, management solutions, and past performance in addition to price.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 481: Current Practices to Set and Monitor DBE Goals on Design-Build Projects and Other Alternative Project Delivery Methods synthesizes current practices and challenges that state departments of transportation (DOTs) face as they set and monitor the Federal Disadvantaged Business Enterprise (DBE) program goals on design-build and other alternative delivery projects. This study focuses on key issues associated with DBE contract goals, including how requirements are established, how submissions are evaluated, how program compliance is monitored through the contract, and what mechanisms are available to state DOTs for enforcement.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 478: Design and Load Testing of Large Diameter Open-Ended Driven Piles documents information regarding the current state of practice with respect to the selection, use, design, construction, and quality control of large diameter open-ended driven piles for transportation structures. This report may provide agencies with information to develop guidance and methods for technical guides and design codes, as well as to identify gaps in knowledge to guide future research.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 482: Work Zone Speed Management documents the current state of practice for work zone speed management, including data, procedures, techniques, and technical issues related to observing and comparing work zone speeds.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 479: Forecasting Transportation Revenue Sources: Survey of State Practices documents current and proposed forecasting methodologies, as well as shortcomings of methods as reported by state departments of transportation (DOTs). The report also includes information about the types of revenue being forecasted, and how satisfied DOTs have been by the accuracy of their projections.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 473: Indefinite Delivery/Indefinite Quantity Contracting Practices examines practices related to the use of Indefinite Delivery/Indefinite Quantity (IDIQ) contracting by transportation agencies for highway design, construction, and maintenance contracts. The synthesis covers multiple aspects of IDIQ practice, including contracting techniques, terminology used by transportation agencies, contract advertising and award practices, successful contracting procedures, pricing methods, risk management issues, and effective contract administration practices.

TRB’s National Cooperative Highway Research Board (NCHRP) Synthesis 469: Impacts of Energy Developments on U.S. Roads and Bridges documents the economic impact of heavy truck traffic related to energy development on the nation’s roads and bridges.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 480: Economic and Development Implications of Transportation Disinvestment examines methods available to estimate disinvestment effects on transportation system integrity within and across modes in urban areas, regionally, and in non-metro areas, and the use of those methods by transportation agencies. The report focuses on macroeconomic effects, intermodal tradeoffs, and methods for broadly informing disinvestment decision making in an era of constrained resources. The report includes information on economic forecasting and travel demand models, risk or probability models, needs models, and benefit and impact models.

TRB's National Cooperative Highway Research Program Synthesis 477: Methods and Practices on Reduction and Elimination of Asphalt Mix Segregation provides guidance on how to reduce or eliminate segregation during aggregate production, mix design, asphalt mix production, mix transport and transfer, and placement. The report also explores options for reducing or eliminating segregate, as well as caveats for what not to do are included.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 470: Maintenance Quality Assurance Field Inspection Practices summarizes practices used by state transportation agencies to support maintenance investments. Appendices A and B are only available through the online PDF document.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 475: Fiber Additives in Asphalt Mixtures summarizes the types of fibers used in asphalt mixtures, their properties, how they are tested, how they are applied, and lab and field performance of the fiber mixes.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 466: Alliance Contracting—Evolving Alternative Project Delivery synthesizes current practices related to the use of alliance contracts around the world, and explores the procurement procedures that have been used to successfully implement alliance contracting on typical transportation projects.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 467: Visualization of Technical Data for Hazard Mitigation and Disaster Response evaluate the tools and techniques used for mitigating geotechnical hazards and responding to geotechnical disasters such as landslides, rockfalls, settlement, sinkholes, and other events.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 487: Public Perception of Mileage-Based Use Fees explores proposals to replace the current motor fuel tax with a road usage charge assessed on vehicle-miles traveled, often called a mileage-base user fee (MBUF). The report identifies and assesses various measures of public opinion on the MBUF concept.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 488: Roundabout Practices summarizes roundabout policies, guidance, and practices within state departments of transportation (DOTs) as of 2015. The synthesis may be used as a reference for state agencies that are creating or updating their roundabout and intersection control policies.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 492: Performance Specifications for Asphalt Mixtures documents the performance tests used in conjunction with volumetric properties for mixtures. Performance tests are intended to extend service life by guiding material selection and proportions. The synthesis provides examples of engineering tools used in the development and implementation of performance specifications for asphalt mixtures, examples of the contents of performance-based specifications (PBS) currently used or in development, information on test program implementation and research efforts related to PBS for asphalt mixtures, and the reported benefits and challenges with implementing PBS.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 484: Influence of Geotechnical Investigation and Subsurface Conditions on Claims, Change Orders, and Overruns documents the extent and type of claims, change orders, and cost overruns from subsurface conditions for state departments of transportation (DOTs). The report also identifies practices used by agencies to reduce such claims, change orders, and cost overruns.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 495: Use of Reclaimed Asphalt Pavement and Recycled Asphalt Shingles in Asphalt Mixtures summarizes current practices for the use of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in the design, production, and construction of asphalt mixtures. It focuses on collecting information about the use, rather than just what is allowed, of high RAP, RAS, and/or a combination of RAP and RAS.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 491: Uses of Mobile Information Technology Devices in the Field for Design, Construction, and Asset Management documents the state-of-the-practice and state-of-the-art applications of state transportation agencies related to their use of mobile information technology (IT) devices. Specifically, the report reviews applications pertaining to the areas of design, construction, and asset management. Mobile IT devices such as laptop computers, mini-laptop computers, handheld multifunctional data collectors, tablets, and smartphones also play a role in bringing the transportation industry into digital platforms.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 486: State Practices for Local Road Safety explores state programs and practices that address local agency road safety. The report focuses on changes in local road safety programs since the legislation of Moving Ahead for Progress in the 21st Century (MAP-21), and the use of Engineering, Enforcement, Education and Emergency Services (4E) approaches to local road safety.

Three-quarters of all road miles in the United States are owned and maintained by local entities. More than half of all fatal crashes occur on rural roads, which are mostly owned by local entities. NCHRP Synthesis 486 documents the state transportation agency programs and practices that address local agency road safety.

The report includes information on state program size, funding sources, and administrative procedures; and noteworthy local/state program partnerships and initiatives to improve safety.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 489: Extending Bridge Service Like Through Field Welded Repairs and Retrofits documents practices associated with field welded repairs on existing steel bridges used by bridge owners. The information presented includes the extent to which field welding is performed on existing bridges, common types of field welded repairs and retrofits, specifications, and quality control practices.

TRB's NCHRP Synthesis 498: Application of Pedestrian Crossing Treatments for Streets and Highways compiles information on the state of existing practices regarding application of pedestrian crossing improvements, and does not produce new guidance. The report includes a survey of state departments of transportation (DOTs) and local transportation agencies, a synthesis of current recommended practice and policy guidance, and a literature review of safety evidence for more than 25 pedestrian crossing treatments.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 497: Post-Extreme Event Damage Assessment and Response for Highway Bridges reviews the procedures that state departments of transportation and two local authorities, New York City and Los Angeles County, use to assess the damage in bridges in response to extreme events and conduct emergency response activities. Extreme events include those with geological sources (such as earthquakes and landslides), from hydro-meteorological sources (such as hurricanes and floods), or those of man-made origin, either accidental (such as truck crashes) or malicious (such as terrorist attacks).

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 485: Converting Paved Roads to Unpaved explores how common and under what conditions paved roads are converted to unpaved.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 490: Practice of Rumble Strips and Rumble Stripes documents current practices used by states installing rumble strips and rumble stripes. The report details and explores variations in state highway agency practices in terms of design, criteria, and locations for installation, maintenance, perceived benefits, communication of benefits, and what is considered as important issues.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 493: Practices for High-Tension Cable Barriers reports on the current state of the practice for high-tension cable barriers (HTCB) used in the medians of access-controlled roadways in the United States. Information on high-tension cable barrier systems related to state agency specifications, special provisions, design standards, and installation and maintenance concerns was collected. Because all of the HTCB systems currently eligible for use on public roads in the United States are proprietary, information was also obtained from each of the manufacturers of these systems.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 494: Life-Cycle Cost Analysis for Management of Highway Assets documents the state of the practice of life-cycle cost analysis (LCCA) and risk-based analysis into state highway agencies' asset management plans for pavements and bridges on the National Highway System. The objective of this project was to develop an inventory of quantitative asset-level, project-level, or corridor-level processes and models for predicting life-cycle costs associated with the preservation and replacement of highway assets. The report includes a literature review, a survey of highway agencies, and case studies that document specific highway agency experiences with LCCA.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 496: Minimizing Roadway Embankment Damage from Flooding documents the state-of-the-practice on how the transportation community is protecting roadways and mitigating damage from inundation and overtopping. This report highlights major issues and design components specific to roadway embankment damage from flooding. It documents the mechanics of damage to the embankment and pavement, and the analysis tools available. The probable failure mechanisms are identified and various design approaches and repair countermeasures are highlighted.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 483: Training and Certification of Highway Maintenance Workers documents front-line maintenance worker training and certification practices for highway transportation agencies in the United States and Canada. The report includes the types of topics being addressed by training and certification programs, the delivery methods used to provide the training, the sources of instruction, and whether material-sharing relationships are being utilized to access training. In addition, the report captures how training is related to performance and the incentives being used by state and provincial agencies to encourage front-line maintenance workers to complete training.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 500: Control of Concrete Cracking in Bridges provides information on methods used to control concrete cracking in bridge superstructures and substructures, and on the influence of cracking on long-term durability. Cracking of concrete in bridges continues to be a concern for bridge owners, particularly with bridge decks exposed to severe environments. The control of cracking for aesthetic, durability, and structural reasons becomes increasingly important as service-life goals are extended and higher-strength concrete, higher-strength reinforcement, and different types of reinforcement are used in bridge construction.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 499: Alternate Design/Alternate Bid Process for Pavement-Type Selection documents the state of the practice in alternate design/alternate bid (ADAB) for pavement-type selection by highway agencies. ADAB is a contracting technique that allows the pavement-type selection decision to be made as part of the procurement process. Contractors are permitted to bid their preferred pavement-type alternative using real-time market pricing for the paving materials.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 505: Current Practices and Guidelines for the Reuse of Bridge Foundations provides guidance on reusing bridge foundations, a sustainable option for many bridge replacement and rehabilitation efforts that can result in time and cost savings as well as reduced mobility impacts and environmental benefits. However, foundation reuse presents significant challenges, including uncertainties in existing foundation condition, remaining service life, and capacity. This synthesis documents current practices and guidelines used by transportation agencies for the reuse of bridge foundations.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 503: Leveraging Technology for Transportation Agency Workforce Development and Training documents how state and local transportation agencies are using information and communication technologies (ICT) to train their workforce. The report explores the planning and resources required to implement and maintain a training and development program and assists agencies that are considering ways to implement, improve, or expand ICT-supported training programs.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 508: Data Management and Governance Practices develops a collection of transportation agency data management practices and experiences. The report demonstrates how agencies currently access, manage, use, and share data.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 504: Strategic Program Delivery Methods explores holistic approaches to maximizing the benefits of time and cost savings when delivering transportation programs, rather than delivering individual projects. While a considerable amount of published research has focused on the process of selecting an optimal project delivery method, this report documents how implementing a variety of delivery methods strategically for a program of projects can improve the delivery of the entire program.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 513: Evolving Debt Finance Practices for Surface Transportation explores a variety of debt mechanisms and tools to finance transportation infrastructure investment. The amount of debt and frequency of issuance vary substantially across states. In most states, provisions included in constitutions or statutes (or combinations of the two) govern the level and form of debt issuance. As well, many states have formal policies that govern debt issuance and management. The study documents new developments in flexible finance tools, including those offered by the federal government.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 501: Pavement Management Systems: Putting Data to Work documents current pavement management practices in state and provincial transportation agencies. The report focuses on the use of pavement management analysis results for resource allocation, determining treatment cost-effectiveness, program development, and communication with stakeholders.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 502: Practices for Establishing Contract Completion Dates for Highway Products documents current methodologies and procedures used by state transportation agencies to estimate contract time for various highway project delivery methods. Establishing contract time is an important part of the highway project development process because it directly impacts project costs, the public, and risk for contractors.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 510: Resource Allocation of Available Funding to Programs of Work explores the decision-making process in state departments of transportation (DOTs) and how they determine resource allocation among different programs. The report documents current processes, techniques, tools, and data used to evaluate and select funding allocations around the country.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 512: Use of Fiber-Reinforced Polymers in Highway Infrastructure documents the current state of the practice in the use of fiber-reinforced polymers (FRPs) in highway infrastructure. The synthesis identifies FRP applications, current research, barriers to more widespread use, and research needs. The objectives of the study are to synthesize published literature on FRP materials in highway infrastructure and to establish the state of current practice of FRP applications in transportation agencies.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 511: Relationship Between Chemical Makeup of Binders and Engineering Performance documents the current practices of departments of transportation (DOTs) in the selection of the chemical composition of a binder used in pavement applications. The study provides information about the selection of binders and postproduction additives and modifiers, as well as corresponding engineering performance.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 506: Effective Utility Coordination: Application of Research and Current Practices documents the state of the practice regarding utility coordination. The objective of the project was to determine how previous research has been incorporated into current practice and compile information about how transportation agencies and utility stakeholders are scoping, conducting, and managing effective utility coordination. The report documents the core elements of effective utility coordination, as reported by state transportation agencies (STAs); current practices to manage consultant-led utility coordination, both stand-alone and those incorporated into design contracts; and current practices to perform in-house utility coordination.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 507: Traffic Signal Preemption at Intersections Near Highway–Rail Grade Crossings documents the current practices of traffic signal preemption deployed at intersections adjacent to railway grade crossing in both the United States and Canada. The study provides information on practices dealing with traffic signal preemption, maintenance, funding, and operations.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 509: Highway Worker Safety identifies how state departments of transportation (DOTs) implement policies using highway worker safety and health data to reduce injuries and manage risk. The report is a synthesis of current proactive safety practices that will be useful when developing or updating policies, programs, or tools to minimize injuries, fatalities, and risk. The study also identifies gaps in knowledge and future research needs.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 514: Statewide and Megaregional Travel Forecasting Models: Freight and Passenger documents current practices and emerging trends with travel forecasting models. The report explores the motivation for and capabilities of statewide and megaregion models, options for extending them and challenges states face doing so, data requirements, how they are used and integrated with other models, institutional constraints, and emerging trends and methods. Several related issues were investigated as well, including performance monitoring, alternative forecasting approaches, and how states are addressing hot topics such as pricing and congestion, multi-state corridors, and new transportation modes.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 515: Practices for Preventing Roadway Departures identifies and summarizes practices being used by state departments of transportation (DOTs) to prevent roadway departure crashes and to identify the data-driven advantages and disadvantages of these practices. More than half of all traffic fatalities result from roadway departure crashes. This type of crash occurs after a vehicle crosses an edge line or centerline or otherwise leaves the traveled way. A variety of engineering strategies, often referred to as countermeasures, have been implemented by state and local agencies to prevent roadway departure crashes and reduce the severity of injuries if crashes do occur. Appendices A through F have been combined into one file and are available separate from the report.

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 516: Tack Coat Specifications, Materials, and Construction Practices provides state agencies across the United States with guidance as they reevaluate their tack coat specifications, the materials they use, and the practices by which the tack coats are placed. Pavement thickness design assumes that pavement works together as one layer, rather than a stack of individual layers working independently. Tack coats function as bonding agents between each lift of a pavement section to create the desired monolithic pavement structure. A tack coat is a sprayed application of asphalt material upon an existing asphalt or Portland cement concrete (PCC) pavement prior to an overlay, or between layers of new asphalt concrete. 

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 518: Staffing for Alternative Contracting Methods documents current practices in state departments of transportation (DOTs) staffing and organizational structure for alternative contracting methods (ACMs). ACMs include design–build, construction manager/general contractor, public–private partnerships, and other innovative contracting techniques. ACMs shift more responsibility to industry for delivering and managing construction projects than traditional design-bid-build projects. As a result, DOTs must make decisions regarding the appropriate levels and mix of staffing for their ACM projects.

 

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 521: Investment Prioritization Methods for Low-Volume Roads documents current practices used by transportation agencies to make investment decisions about low-volume roads. Current transportation asset management practices for low-volume roads typically use asset condition, traffic, and safety metrics to prioritize investment decisions for preservation, maintenance, repair, and replacement projects. However, these metrics do not fully measure the significant value for the wider economy and society that low-volume roads can provide. This publication also addresses the challenges that decision makers may face to communicate the value of such investments to stakeholders in an era of limited funds and constantly changing demands on the transportation system.

WITHDRAWN

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 524: Aggregate Quality Requirements for Pavements Aggregate Quality Requirements for Pavements documents transportation agency requirements for the quality of aggregates for various pavement types. Constructing and maintaining pavements requires an abundant and dependable supply of quality aggregates. Aggregate comes from a wide range of materials, including quarried rock, sand, and gravel, and materials such as slag, reclaimed asphalt pavement, and recycled concrete aggregate. While all transportation agencies have specifications for aggregate quality, there is wide variation in what different agencies consider suitable aggregates for specific applications.

The report is accompanied by the following appendices:

• Appendix A: Survey Questionnaire
• Appendix B: Compilation of Survey Responses Provided by Agency Respondents
• Appendix C: Survey Respondent Information
• Appendix D: Links to Approved Aggregate Lists and Specifications Published by Agencies

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 525: Practices in One-Lane Traffic Control on a Two-Lane Rural Highway identifies innovative practices and devices for establishing one-lane traffic control on rural two-lane highways. Temporary traffic control, also known as maintenance of traffic, is critical to minimizing congestion and maintaining mobility during planned and unplanned activities as well as providing a safe work zone for both road users and workers. Innovative examples of one-lane two-way traffic control operations at roundabouts and applications of temporary portable rumble strips and driveway assistance devices are also discussed in this synthesis, providing additional insights on the state of the practice. 

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 528: Analyzing Data for Measuring Transportation Performance by State DOTs and MPOs summarizes what data state departments of transportation (DOTs) and metropolitan planning organizations (MPOs) are using and how they are measuring transportation performance. Knowledge about transportation data already exists, but may be fragmented, scattered, and unevaluated. This report synthesizes current knowledge and practice about data management to help transportation organizations learn about effective practices. The report also identifies future research needs. This synthesis includes appendices to the contractor's final report.

Freight investment project prioritization, which is used to assist in planning and programming decisions, differs widely in importance across states. One of the reasons for the difference in importance is the fact that freight projects are costly, and state departments of transportation (DOTs) face limited resources to implement them. The National Cooperative Highway Research Program's NCHRP Synthesis 542: Prioritization of Freight Investment Projects identifies the state of the practice of freight project prioritization and common steps across all state DOTs in the nation. State DOTs have a variety of motivations for freight project prioritization, including the FAST Act. For DOTs to receive additional federal funding, a priority list of freight projects must be produced. However, because the FAST Act regulations do not include a specific methodology to help DOTs rank their freight projects, many different processes are used by the state DOTs for ranking. This report synthesizes the available literature on the subject so that DOTs creating a prioritization process can identify successful practices in the current state of the practice.

The uses and levels of maturity of five advanced technology areas visualization and modeling, interconnected technologies, safety technologies, instrumentation and sensors, and unmanned aircraft systems in transportation highway construction projects are documented in TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 534: Emerging Technologies for Construction Delivery. The synthesis also investigates the implementation barriers and success factors for these technology areas and discusses the lessons learned as noted by state DOTs in their effort to study, test, and implement a new construction technology.

As the highway construction industry infuses more technologies into the process of project delivery, state DOTs have an opportunity to realize improved project performance regarding cost, schedule, and quality.

The Federal Highway Administration (FHWA) Every Day Counts (EDC) initiatives promote the use of various advanced and emerging technologies (e.g., automated machine guidance, unmanned aircraft systems, building information modeling, handheld instruments and devices, and work zone intrusion detection systems).

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 536: Bridge Demolition Practices documents practices used by bridge owners to manage and administer bridge demolition in construction projects.

Each year hundreds of bridges are rebuilt or are entirely replaced as part of highway construction projects. Bridge reconstruction or replacement work often entails demolition of part or all of the bridge structure.

Unintended events resulting in injury, project delays, and traffic disruptions can occur and have occurred during bridge demolition activities. The intention of this synthesis report is to assist in better understanding how to reduce risk associated with bridge demolition.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 533 identifies the current state of practice among state departments of transportation (DOTs) regarding selection and setup of very short duration work zone (VSDWZ).

The report presents case examples of four state DOTs along with an in-depth analysis of the VSDWZ policies of these states. The case example agencies have developed specific guidance on the topic for their jurisdictions.

VSDWZ activities are those activities not defined in the Manual on Uniform Traffic Control Devices (MUTCD) under short duration work zone or temporary traffic control (TTC) zones. These activities are usually 1 to 20 minutes long and include maintenance activities (e.g., performing temporary patching, picking up debris, or placing traffic count tubes) where TTC is not set up.

VSDWZ activities reduce the exposure of workers to risk and the inconvenience to traffic that standard TTC zones would create. Current policies and practices in place at various agencies for VSDWZ activities vary substantially. The work-zone setup also varies by the type of maintenance or other very short duration activity and roadway classification (e.g., speed, AADT, and number of lanes). Historically, during those activities, a large number of worker fatalities have occurred.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 537: Impact of Asphalt Thickness on Pavement Quality documents transportation agency policy for lift thickness and minimum compaction requirements on resultant asphalt pavement quality. To achieve expected pavement performance, it is important that asphalt concrete (AC) have adequate density. A critical factor in achieving this density is the ratio of lift thickness to nominal maximum aggregate size (t/NMAS). The information in the report is designed to help make agencies aware of a range of practices other agencies use to achieve a desired t/NMAS ratio, ensuring that density of AC is adequate to meet expected pavement performance.

Current practices used by state departments of transportation to design and manage the urban freeway roadsides (UFRs) environment is the focus of National Cooperative Highway Research Program (NCHRP) Synthesis 539: Landscape Development and Management Practices for Urban Freeway Roadsides.

The urban freeway roadsides (UFRs) for this synthesis are those roadsides associated with high visibility urban freeways with limited pedestrian access, such as wider medians, interchanges, and overpasses.

The UFR is part of a greater urban environment with broad social, political, economic, and environmental implications for management. There are numerous UFR stakeholders, such as their respective municipalities, residents, adjacent landowners and businesses, traveling public, and state DOTs, and each has specific requests, requirements, and considerations. Among these are an acceptable level of maintenance and stakeholder expectations for aesthetics.

State departments of transportation (DOTs) recognize their roadway systems are assets that need management and acknowledge that pavements and other infrastructure routinely require resurfacing, restoration, and rehabilitation because their integrity degrades over time. However, the UFR and its respective urban freeway systems may not receive the same routine restoration. The vegetation installed at the time of roadway construction ages with the surrounding infrastructure. Decades after initial installation within the UFR, transportation agencies have mature landscapes that may be near the end of their life cycle.

The inability to adequately access and maintain these areas can result in failure of planted vegetation, loss of investment, and public criticism of state DOTs. The UFR is part of state DOTs’ highway system investment facing many challenges as freeway renovations and expansions encroach on limited right-of-way (ROW) areas available for landscape development. As the size of these areas decreases, so does the ability of maintenance workers and equipment to safely access and maintain them.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 522: Managing State Transportation Research Programs identifies the current state of practice of managing state transportation research programs. The report highlights existing resources, desired individual skill sets, core competencies, and structures that are in place for departments of transportation (DOTs) to manage and conduct transportation research, especially federally funded research.

In essence, NCHRP Synthesis 522 addresses how transportation agencies organize and manage their research programs to strive for quality and positive impacts on the transportation system over time (value). The report includes a four-dimensional framework to analyze and shed light on how state DOT research programs with differences in agency needs, resources, and constraints are able to produce programs of high quality and value.

State transportation agencies conduct applied research with a goal of ultimately creating new knowledge to enhance the transportation system. Agency research as an activity requires special skills and capabilities—it convenes practitioners, scholars, and policy makers to identify and pursue the knowledge that is most needed.

These and other attributes of research make it unlike other DOT functions such as planning, programming, construction, maintenance, and operations, even though it eventually enables agencies to perform those functions. The payoffs and innovative outcomes of research can be significant and valuable, although they are rarely immediate.

The objective of this synthesis is to document information on pedestrian crashes relative to traffic speed in urban core areas. The report will gather information on reported impact speeds for pedestrian collisions. The synthesis will also document key pedestrian safety policies that have been implemented in support of Vision Zero, a strategy to eliminate all traffic fatalities and severe injuries, while increasing safe, healthy, and equitable mobility. X

The past few years have seen some significant advances in concrete technology. For example, newer concrete incorporating advances in admixtures and cementitious materials has emerged.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 544: Concrete Technology for Transportation Applications documents how state departments of transportation select and deploy concrete technologies in the construction of transportation facilities.

Concrete technology is also facing some emerging challenges that need to be addressed. These challenges include the present or future depletion of high-quality aggregates in some parts of the country, changes to power generating plants that will reduce the supply and consistency of acceptable fly ashes, and the incorporation of reclaimed or traditionally landfilled materials such as recycled concrete aggregate (RCA) into concrete.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 538: Practices for Online Public Involvement summarizes current practices regarding online public participation strategies being used by state departments of transportation (DOTs), as well as explores the effectiveness of using these strategies and tools. Online public participation methods offer agencies the potential for expanded participation and also present new challenges and demand new thinking about the appropriate mix of techniques in a public participation program, communication protocols, staffing and skill requirements, and how best to integrate emerging online engagement tools with traditional face-to-face methods such as public meetings.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 532: Seismic Design of Non-Conventional Bridges documents seismic design approaches and criteria used for “non-conventional” bridges, such as long-span cable-supported bridges, bridges with truss tower substructures, and arch bridges.

Design of conventional bridges for seismic demands in the United States is based on one of two American Association of State Highway Transportation Officials (AASHTO) documents: the AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications (AASHTO BDS) (1) or the AASHTO Guide Specifications for LRFD Seismic Bridge Design (Guide Spec) (2). The stated scope of these documents for seismic design is limited to conventional bridges.

Non-conventional bridges outside the scope of these two AASHTO documents, such as cable-supported bridges and long-span arch bridges, are typically high value investments designed with special project criteria. There is no current AASHTO standard seismic design criteria document specific to these non-conventional bridges. Seismic design criteria for these non-conventional bridges are typically part of a broader project-specific criteria document that addresses the special character of the bridge type.

Public–private partnerships (P3s) can provide solutions to the project delivery challenges faced by state departments of transportation (DOTs) and local transportation agencies in delivering surface transportation infrastructure by aligning risks and rewards between public and private sectors, accelerating project delivery, improving operations and asset management, realizing construction and operational cost savings, and attracting private-sector equity investment. P3s are becoming an increasingly important option for financing and implementing critical improvements to U.S. surface transportation infrastructure. As interest in P3s grows, U.S. transportation agencies and stakeholders evaluating the potential benefits of P3s have raised issues relating to the role of private equity in these transactions. Recognizing the complexity and challenges of structuring a highway or bridge P3 compared to a conventional procurement, the objective of NCHRP Synthesis 540: Leveraging Private Capital for Infrastructure Renewal is to bridge the knowledge gap on the role of equity in surface transportation P3 projects and to document current practices relating to private-equity investments in small-scale and large-scale transportation infrastructure projects.

Freight investment project prioritization, which is used to assist in planning and programming decisions, differs widely in importance across states. One of the reasons for the difference in importance is the fact that freight projects are costly, and state departments of transportation (DOTs) face limited resources to implement them. The National Cooperative Highway Research Program's NCHRP Synthesis 542: Prioritization of Freight Investment Projects identifies the state of the practice of freight project prioritization and common steps across all state DOTs in the nation. State DOTs have a variety of motivations for freight project prioritization, including the FAST Act. For DOTs to receive additional federal funding, a priority list of freight projects must be produced. However, because the FAST Act regulations do not include a specific methodology to help DOTs rank their freight projects, many different processes are used by the state DOTs for ranking. This report synthesizes the available literature on the subject so that DOTs creating a prioritization process can identify successful practices in the current state of the practice.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 531 documents agency practices, challenges, and successes in conducting automated pavement condition surveys.

The report also includes three case examples that provide additional information on agency practices for conducting automated pavement surveys.

Pavement condition data is a critical component for pavement management systems in state departments of transportation (DOTs). The data is used to establish budget needs, support asset management, select projects for maintenance and preservation, and more.

Data collection technology has advanced rapidly over the last decade and many DOTs now use automated data collection systems.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 551: Highway Hydraulic Engineering State of Practice documents significant changes in highway hydraulic engineering practices implemented by state departments of transportation (DOTs) over the past decade.

The synthesis focuses on eight subtopics of highway hydraulic engineering: roadway drainage; culvert aquatic organism passage; bridge scour computations and countermeasures; advanced hydraulic modeling; regulatory requirements; floodplain impacts and mitigation; coastal hydraulics; and alternative project delivery methods.

Most U.S. state departments of transportation (DOTs) are collecting weigh-in-motion data with a wide variety of sensor types and using them in a variety of applications. Many agencies use WIM data to aid in pavement design, although most are not currently using a Pavement ME (mechanistic-empirical) Design application. WIM for bridge and asset management purposes is used much less often.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 546: Use of Weigh-in-Motion Data for Pavement, Bridge, Weight Enforcement, and Freight Logistics Applications documents how DOTs incorporate weigh-in-motion data into such applications as bridge and pavement design and management, load ratings, weight enforcement support, and freight planning and logistics.

Managing access connections to roadways is vital to safety and operational performance of roadways for all users. Given the separation of authority between state and local governments over land development and access, intergovernmental coordination is integral to effective access management.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 549: Incorporating Roadway Access Management into Local Ordinances documents regulatory tools and practices used by local governments to implement access management, as well as provides examples of how state transportation agencies are coordinating with local governments to advance access management objectives.

The review of local ordinances and state and local government coordination practices indicates that access management is being actively implemented throughout the United States. Typical features of local ordinances reviewed included access classification schemes and corresponding spacing standards, interparcel cross access requirements, intersection functional area or corner clearance standards, limits on driveways per site, unified access and circulation requirements for outparcels, allowances for deviations from standards, and access permitting and development (site plan) review procedures and criteria.

Geotechnical instrumentation and monitoring technologies have been used to inform safety, operational, and treatment decisions for unstable slopes.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 554: Advances in Unstable Slope Instrumentation and Monitoring documents and synthesizes the state of practice for implementation and use of advancements in unstable slope instrumentation and monitoring by state departments of transportation over approximately the last decade.

The types of instrumentation and monitoring technologies range from devices installed on or in slopes to remote-sensing methods from ground, aerial, or satellite-based systems.

Pavement warranties have been common in the United States at various points in time, coming back into favor during the 1990s. While there is no national pavement warranty standard, agencies have developed their own specifications with varying criteria.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 553: Performance-Based Pavement Warranty Practices documents highway agency practices associated with the use of performance-based pavement warranties, focusing on asphalt, concrete, and composite pavement projects (new, preservation, and rehabilitation) with warranty periods of at least one year.

State departments of transportation often encounter public resistance to alternative intersections, with 86% of respondents in a new survey of state DOTs agreeing or strongly agreeing that public resistance hinders their implementation. Public resistance can vary among projects based on intersection type and whether the project was initiated at the local or state level.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 550: Alternative Intersection Design and Selection documents the evaluation and selection processes within state departments of transportation (DOTs) for intersection projects.

Roundabouts are the most widely implemented type of alternative intersection. Ninety percent of state DOTs that responded to the synthesis survey reported having at least one roundabout in their jurisdiction open and operational. Roundabouts also had the highest reported number of facilities in project development as 88% of respondents indicated there was at least one roundabout under development at their DOT.

Sixty-eight percent of the states who responded to a survey indicated their agency has a documented process for as-built development. They said handwritten notes were the most commonly used method to capture as-built data (86%), followed by electronic notes (76%), and then photographs (33%). Some states use more than one option to capture as-built data.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 548: Development and Use of As-Built Plans by State Departments of Transportation examines the current state of the practice in as-built development and use across the United States.

Over the years, as-built plans have been the method used by the construction industry to capture and record construction changes and additions that are not represented in the original plan drawings. The accuracy and completeness of these plans are essential for operations, maintenance, and rehabilitation of current transportation infrastructure.

Scaling loose rock from highway rock slopes is an important aspect of improving rock slope safety in mountainous areas, according to input from 42 state departments of transportation and two regional divisions of the Office of Federal Lands Highway.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 555: Estimating and Contracting Rock Slope Scaling Adjacent to Highways documents current rock slope scaling practices adjacent to highways.

An appendices document is also included as part of the publication.

Performance testing of asphalt mixtures is becoming more widespread for a variety of reasons and with a variety of testing devices. The tests results are sensitive to the procedures used in preparation of the specimens. Guidelines exist for conducting the tests; however, they do not all provide uniform or comprehensive direction for fabricating test specimens.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 552: Practices for Fabricating Asphalt Specimens for Performance Testing in Laboratories documents procedures related to laboratory fabrication of asphalt performance test specimens at state departments of transportation (DOTs) and at partner laboratories that conduct performance testing on behalf of DOTs.

Current legislation and subsequent asset management rules require state departments of transportation (DOTs) to conduct statewide evaluations of roads, highways, and bridges that have required repair and reconstruction activities two or more times since 1997 due to emergency events as declared by the president of the United States or by a state’s governor.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 556: Asset Management Approaches to Identifying and Evaluating Assets Damaged Due to Emergency Events furnishes documentary evidence of the approaches that state DOTs have taken to identify and evaluate locations where highway assets have been repeatedly damaged and to identify considerations that have been made for mitigating the risk of recurring damage to assets in those areas.

The report is intended to help transportation agencies with building data sets and tools that support the evaluation of damage to assets associated with emergency events and to illustrate methodologies that are being used to integrate these risks into asset investment decisions.

Digital terrain models (DTMs) are three-dimensional (3D) models of the ground surface showing natural features such as ridges and breaklines.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 560: Practices for Construction-Ready Digital Terrain Models documents processes and strategies used by state departments of transportation (DOTs) for the use and transfer of DTMs from design into the construction phase of highway projects.

Incompatibility between aggregate type and asphalt binder, presence of standing water or water under pressure in the pavement layers, and improper construction practices are some of the many factors that influence moisture susceptibility of flexible pavements.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 595: Practices for Assessing and Mitigating the Moisture Susceptibility of Asphalt Pavements documents practices used by state departments of transportation to prevent or to minimize moisture damage in hot-mix asphalt pavements.

The objective of this synthesis is to gather information on the practices used by bridge owners to repair and maintain post-tensioned bridges, both in service and during construction. The goal is to further facilitate knowledge transfer across state DOTs, aiding bridge owners in the identification, repair and maintenance practices that are working.

Pavement preservation is broadly acknowledged to provide network-wide benefits such as extending pavement life, enhancing system performance, reducing operation and maintenance costs, and improving safety. However, the performance of each pavement preservation project hinges on many factors.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 565: Maintenance and Surface Preparation Activities Prior to Pavement Preservation Treatments documents the types of maintenance and surface preparation activities performed by departments of transportation before pavement preservation treatments are applied.

Public–private partnerships (P3) allow public transportation agencies to attract private financing to deliver needed highway infrastructure and not have to wait until the required funding is fully in place via traditional state and federal sources.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 563: Performance Metrics for Public–Private Partnerships documents key performance metrics used in various long-term P3 contracts for the delivery of highway projects, including services by Departments of Transportation (DOTs).

Initial efforts to define and collect bridge element data in the United States started in the late 1990s with the development and implementation of bridge management systems (BMSs). Over the years, the bridge management community provided feedback and made suggestions to improve the bridge element inspection methodology.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 585: Bridge Element Data Collection and Use documents current state departments of transportation (DOTs) practices and experiences regarding collecting element-level data and ensuring data accuracy. The synthesis also examines how state DOTs are using the data from inspection reports.

While it is recognized to be in the public interest to permit the installation of utility infrastructure in roadway rights-of-way, the practice has contributed to utility-related issues being one of the leading causes of delays for transportation projects. Subsurface utility engineering (SUE) is an approach state departments of transportation (DOTs) have implemented to locate utilities and assist their project-development teams with avoiding these issues.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 583: Implementation of Subsurface Utility Engineering for Highway Design and Construction documents state DOT use and practices related to SUE and specifically examines how and when SUE is implemented during the project-design and delivery processes.

To make work zones safer, state departments of transportation (DOTs) use smart technologies with specialized components, such as sensors, communications, software, and electronic equipment, to manage traffic and operations and disseminate traveler information.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 587: Use of Smart Work Zone Technologies for Improving Work Zone Safety reviews and documents state DOT practices and implementation challenges regarding the use of smart work zone technologies designed to improve safety for motorists, construction and maintenance workers, and other users of the transportation system.

State departments of transportation (DOTs) have been investing in 3D modeling and sharing 3D digital models with contractors. Some DOTs have piloted the use of 3D digital models as contract documents, others continue to provide contractors with 3D digital models for information purposes, and some have not begun using 3D digital models in construction.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 593: 3D Digital Models as Highway Construction Contract Documents details the current state of DOT practices for delivering 3D digital models to highway contractors and the use of these models as part of the legal construction contract document.

Visualizations are tools for analyzing, reporting, and communicating the complexities of a transportation system and for synthesizing these intricacies into presentations that can be easily understood.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 584: Visualization of Highway Performance Measures documents current practices and methods used by state departments of transportation (DOTs) for visualizing highway performance measures and their use of visualization techniques for communication and decision support.

Supplemental to the publication is a Presentation of Visualization Examples.

Although the use of recycled asphalt materials (RAM) in new asphalt mixtures can reduce the amount of virgin and nonrenewable materials required and increase the rutting resistance of pavements, it may also compromise cracking resistance. To mitigate this issue, asphalt mixtures containing RAM may require the use of a softer binder or recycling agent (RA).

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 586: Use of Recycling Agents in Asphalt Concrete Mixtures documents current state department of transportation (DOT) practices and procedures related to the use of RAs in asphalt mixtures containing RAM.

While there are no national standards for rock slope design and rockfall management, many state departments of transportation (DOTs) have developed their own design goals and objectives.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 588: Design Practices for Rock Slopes and Rockfall Management documents DOT practices for the design of rock slopes and rockfall mitigation systems.

Technology solutions are in no short supply for state departments of transportation across the United States. With advancements in geospatial accuracy, cost reduction for technology components, and a need for effective staff utilization, a wealth of products and systems are becoming attractive options in the delivery of highway projects.

The TRB National Cooperative Highway Research Program's NCHRP Synthesis 594: Technological Capabilities of Departments of Transportation for Digital Project Management and Delivery details a number of solutions and documents successful uses of technologies.

The objective of this synthesis is to document state DOT practice regarding safety incentive and disincentive programs for DOT highway construction and maintenance crews, related motivational techniques, and written policies or training to implement these programs.

The objective of this synthesis is to document current state DOT practices that leverage social media data for emergency preparedness, response, and recovery.

The objective of this synthesis is to document current state DOT practices related to utility as-built collection and use, including approaches taken by DOTs in working with utility companies for sharing as-built information.

The objective of this synthesis is to document current state DOT practices for bioretention de-sign, construction, and maintenance.

The objective of this synthesis is to document the extent to which state DOTs have developed local resistance factor calibration, which factors have been calibrated, and how locally calibrated factors have been used.

The objective of this synthesis is to document state DOT practices for curing pavement concrete including procedures, materials, application rates, timing, QC/QA procedures, and specific measures adopted when paving under adverse weather conditions.

The objective of this synthesis is to document current strategies and practices in use by state DOTs to facilitate and coordinate the provision and operation of EV charging facilities. The synthesis will also include current plans to address the future maturity of EV charging, such as preparation for medium and heavy-duty electrification. The final report is available at: https://doi.org/10.17226/27134.

The objective of this synthesis is to document the current practice of state DOT use of UAS as a tool for stormwater BMP inspections.

The objective of this synthesis is to document state DOT uses of distributed rainfall models. The synthesis will focus on the use of distributed rainfall methods for hydrologic analyses of bridge projects and highways in floodplains.

The objective of this synthesis is to document the practices employed by state DOTs to provide or improve access to existing vehicle bridges for active transportation users. The synthesis will only focus on existing vehicle bridges and not on new construction. The final report is available at: https://doi.org/10.17226/27063.

The purpose of this proposed synthesis is to document current state DOT practices of tolerance management for steel bridge elements.

The objective of this synthesis is to document current state DOT practices regarding the use of probe data in freight planning and modeling, and operations management applications.

The objective of this synthesis is to document methods and practices employed by departments of transportation (DOTs) to identify critical findings for tunnel functional systems. 

The objective of this synthesis is to document current state DOT practices for field and laboratory moisture measurement for foundations and slopes for pavements and structures.

The report is available.

The objective of this synthesis is to document current DOT practices related to RSAs.

The objective of this synthesis is to document state DOT practices related to data models and data stewardship of ancillary assets. 

The objective of this synthesis is to document state DOT practices of visualization for public involvement throughout the lifecycle of plans, programs, and projects.

The objective of this synthesis is to document state DOT hydraulic and hydrologic engineering considerations and practices for design and construction of temporary facilities in streams and rivers. 

The objective of this synthesis is to document state DOT current practices related to quality checking software-based structural analysis models for bridges and structures. The synthesis will focus on the responsibilities of the engineer in checking structural analysis models.

The objective of this synthesis is to document state DOT practices of programmatic approaches to ACMs.

The objective of this synthesis is to document current practices used by state departments of transportation (DOTs) to detect, guide, and capture heavy vehicles speeding on steep downgrades.

The objective of this synthesis is to document state DOT practice on identification, investigation, design guidance and requirements, prevention, and mitigation of surficial slope failures. 

The objective of this synthesis is to document state DOT innovation programs and initiatives, areas of focus on the innovation spectrum, and associated activities.

Water infiltration is a common problem in tunnels and contributes to the deterioration of the structure and elements within and creates hazards such as icicles and slippery roadways.  A variety of methods exist today to address water infiltration but understanding the appropriate mitigation to use in specific circumstances and what limitations accompany that mitigation is the key to success.  The objective of this synthesis is to document practices used by state department of transportation (DOT) tunnel owners to control leaks.

Information for this study was gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected DOTs.  Case examples of four state DOTs provide additional information on practices for controlling tunnel leaks.  

Martha Averso, Tom Leckrone, and Katie Clever, Gannett Fleming, Inc., collected and synthesized the information and wrote the report. The members of the topic panel are acknowledged on page iv.  This synthesis is an immediately useful document that records practices that were acceptable within the limitations of the knowledge available at the time of its preparation.  The report can be found here.

 

The objective of this synthesis is to document current DOT practices related to advancing gender equity in their workforce.

The objective of this synthesis is to document state DOT current practices to capture maintenance costs in their MMS, the level of detail captured, and the level of integration and synchronicity with financial systems and ERPs.

The objective of this synthesis is to document practices used by state departments of transportation (DOTs) related to the use of corrosion resistant reinforcing bars. 

The objective of this synthesis is to document state DOT practices for using SCMs in concrete.  

The objective of this synthesis is to document practices used by state DOTs for implementing qualification and/or certification programs for materials sampling and testing personnel in accordance with 23 CFR 637 Subpart B.

The objective of this synthesis is to document practices and decision-making used by state DOTs for planned bridge replacements in complex scenarios.

The purpose of this synthesis is to document state DOT practices, tools, and approaches for managing compliance with state and federal construction stormwater permit requirements. 

The objective of this synthesis is to collect resources and document practices used by state DOTs in training and/or setting qualifications of the bridge construction inspection workforce.

The objective of this synthesis is to document practices used by state DOTs for flexible and composite pavement maintenance for wide transverse and longitudinal cracks and joints.

 

The objective of this synthesis is to document practices used by state DOTs regarding the use of safety leading indicators to track and prevent occupational injuries and other incidents.

The objective of this synthesis is to document management and maintenance practices used by state DOTs to enhance resiliency of existing roadway and embankment culverts.

The objective of this synthesis is to document state DOT practices and activities in designing, constructing, and monitoring structures that deliver aquatic organism passage.

The objective of this synthesis is to document practices used by state DOTs for managing selected ancillary transportation assets, including levels of maturity and variability of practice across state DOTs.