BACKGROUND
Pavement marking materials provide delineation on highways around the world. Commonly used pavement marking materials include paint, thermoplastic, epoxy, and preformed tape. The performance of these materials, including their initial and lifetime retroreflectivity and their durability, as well as their costs vary greatly by material type and sometimes by location and climate. In addition, many agencies supplement pavement markings with pavement markers on certain types of facilities.
Two recent projects, "Evaluation of All Weather Pavement Markings" conducted for FHWA and "Determining the Effectiveness of Pavement Marking Materials" carried out by the Virginia Transportation Research Council, identified the need for further research to more accurately assess the safety impact of pavement marking materials, when used singly or in combination with pavement markers, for the purpose of evaluating their real cost-effectiveness, defined here as the safety impact of the marking or marker in relation to its performance and cost.
The results of this research will support the advancement of management systems for pavement markings and roadway delineation through development of (1) guidelines for the application of "right" markings and markers, whether singly or in combination, on streets, roads, and highways and (2) a supporting model performance-based specification.
OBJECTIVE
The objective of this project is to develop guidelines for use of pavement marking materials and markers based on their safety impact and cost-effectiveness. Within the scope of this project the terms "pavement marking materials and markers" and "pavement markings and markers" shall specifically refer to those now in common use, either singly or in combination, for longitudinal delineation on all classes of roadways.
Accomplishment of the project objectives will require the following tasks.
PHASE I (1.) Survey state DOTs and other relevant organizations to obtain data, analyses, and research results on (1) the safety impact, performance measures, and cost-effectiveness of pavement markings and markers and (2) agency use of performance-based specifications for these materials. This task shall emphasize the identification of data and analyses available from sources such as public- and private-sector materials testing laboratories, materials manufacturers and suppliers, and the National Transportation Product Evaluation Program (NTPEP) and from state pavement-marking management systems. Of particular interest are (1) the policies and procedures used by agencies for the purchase of materials, their application, and their long-term performance and (2) the use of performance-based specifications for these purposes. (2.) Review relevant practices, research findings, and other information worldwide on the safety impact, performance measures, and cost-effectiveness of pavement markings and markers. (3.) Based on the findings of Tasks 1 and 2, identify significant gaps in the understanding of the safety impact of pavement markings and markers and the cost-effectiveness of current practices for their use. Submit a letter report for NCHRP review and approval that (1) presents options for filling these gaps, including key tasks, data collection and analysis protocols, estimated budget, and schedule and (2) recommends one option to be developed into a detailed work plan in Task 4, based on the agency's judgment of the potential value of the information it will provide towards meeting the project objective. Meet with the project panel to discuss the preliminary findings of Tasks 1 and 2 and possible options for the Task 6 work plan. (4.) Prepare a detailed work plan for the option approved in Task 3. In the plan, propose methodology (which may include the use of a meta-analysis or the Delphi process) to (1) correlate the safety impact of pavement markings and markers with their performance (e.g., retroreflectivity) and (2) determine their cost-effectiveness using available cost data. The work plan shall emphasize analysis of existing databases in lieu of new field evaluations. (5.) Within 10 months of the effective date of the contract, submit an interim report of the findings of Tasks 1 through 4, including the detailed work plan. In the report, provide a sound rationale for proceeding with Phase II and a candid assessment of its probability for success. The research agency will be required to meet with the project panel approximately 1 month later to obtain NCHRP approval to proceed with Phase II; lacking a satisfactory rationale and assessment, the project will be terminated at the conclusion of Phase I.
PHASE II (6.) Conduct the work plan approved in Task 5 to (1) develop the required correlations between the safety impact of pavement markings and markers and their performance and (2) determine the cost-effectiveness of pavement markings and markers. (7.) Using the results of Task 6, identify and rank the primary variables (e.g., geometrics, AADT, vehicle mix, climate, class of roadway, pavement type, pavement-management strategies) that determine the relative cost-effectiveness of pavement markings and markers. Develop a matrix for considering the effect of multiple variables and their threshold values in the selection of pavement markings and markers for a given situation. (8.) Using the matrix developed in Task 7, develop guidelines for the general or project-specific selection of pavement markings and markers on the basis of their safety impact and cost-effectiveness. The guidelines will include illustrative examples for agency use in creating policies and procedures. (9.) Identify how the matrix and guidelines developed in Tasks 7 and 8 may be integrated into agency pavement-marking/marker management systems and into relevant AASHTO, ITE, TRB, and FHWA handbooks and manuals. (10.) Propose a model performance-based specification and associated criteria for procurement of pavement markings or markers. (11.) Prepare a final report that summarizes the results, findings, and conclusions of the research. Submit a database in electronic format with the data and analytical results of the work plan conducted in Task 6.
STATUS: All work on the project is completed.
PRODUCT AVAILABILITY: The revised final report is available online as NCHRP Web-Only Document 92. A summary of the revised final report has been published as NCHRP Research Results Digest 305.
