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The National Academies

NCHRP 17-34 [Completed]

Prepare Parts IV and V of the Highway Safety Manual

  Project Data
Funds: $200,000
Research Agency: Kittelson & Associates, Inc.
Principal Investigator: John Zegeer
Effective Date: 6/17/2005
Completion Date: 12/31/2006

BACKGROUND

An extensive and ground-breaking initiative is underway to develop a Highway Safety Manual (HSM). Development of the HSM was initiated by a Transportation Research Board Joint Subcommittee (now Task Force). Portions of the Manual are being developed under several NCHRP projects and the HSM will be recommended for adoption by AASHTO. The HSM will serve as a tool to help practitioners make planning, design, and operations decisions based on safety. It will serve the same role for safety analysis that the Highway Capacity Manual (HCM) serves for traffic operational analysis. The purpose of the HSM will be to provide the best factual information and tools in a useful and widely accepted form to facilitate the explicit consideration of safety in decisionmaking. Development of the HSM will be a significant and lengthy effort; it is detailed in the HSM work plan (the plan and other documents related to the HSM are located on the TRB HSM Task Force website noted under Task 1 below). The related NCHRP projects are shown in the following table.
Committed Projects
HSM Part
Scope of Work
Status as of 1 September 2004
NCHRP Project 17-18(4) Part III, Chapter 8 Develop HSM annotated outline, prototype chapter (two-lane rural roads), and work plan Completed
NCHRP Project 17-26 Part III, Chapter 10 Develop urban and suburban predictive model Start: June 2003, 24-month contract
NCHRP Project 17-27 Parts I and II, Chapters 2 - 7 Develop Part I and Part II Start: May 2004, 24-month contract
NCHRP Project 17-29 Part III, Chapter 9 Develop multilane rural predictive model Start: July 2004, 24-month contract
NCHRP Project 17-34 Parts IV and V,
Chapters 11-16
Develop Part IV and Part V RFP advertised, proposals due to NCHRP on October 28, 2004

Ongoing work is focused on developing the safety prediction models or algorithms needed to make quantitative estimates of the safety performance for specific highway types and on preparing Parts I and II of the HSM. The initial modeling efforts are expected to result in a major change in the approach to highway safety analyses. Enhancements to the models are expected in future editions of HSM.

Parts IV (Roadway Safety Management) and V (Safety Evaluation) will provide valuable guidance to the user on incorporating safety considerations into highway planning, design, and operations. This project is an integral part of the work plan for the first edition HSM developed under NCHRP Project 17-18(4) and constitutes Project C-5 in that work plan. The work plan approved by the TRB HSM Task Force is available for review at http://www.wsdot.wa.gov/eesc/design/jsc.

The research will prepare a draft of Parts IV and V in a form that is consistent with the plans for the rest of the HSM. In developing Part IV and V, the research shall include critical reviews of published literature and maintain liaison with ongoing research projects such as those in the above table and with FHWA's Interactive Highway Safety Design Model (IHSDM); FHWA's SafetyAnalyst; TRB's effort to develop a Human Factors Guide; AASHTO's Transportation Safety Information Management System (TSIMS); and AASHTO's Strategic Highway Safety Plan.

OBJECTIVE

The objective of the research is to prepare Parts IV and V of the Highway Safety Manual.

These two sections will cover roadway safety management (improvement of roadway systems) and safety evaluations, providing tools to help practitioners make planning, design, and operations decisions based on safety. Parts IV and V, as developed under this project, should be in as near final form as possible for incorporation into the HSM. It is expected that Part IV (Roadway Safety Management) will include chapters on identification of candidate locations, investigation and analysis of safety conditions at specific sites, selection of countermeasures, economic appraisals of sites under consideration, and prioritization of improvement projects. Part V (Safety Evaluation) will contain information on measuring the safety effect of implemented countermeasures.

Accomplishment of the project objective will require at least the following tasks.

TASKS (1.) Review the Highway Safety Manual (HSM) production documents, including but not limited to the annotated outline and prototype chapter, which are included in the final report for NCHRP Project 17-18(4); the revised HSM work plan; and other HSM documents. The final report for Project 17-18(4) is available online as NCHRP Web Document 62 on the TRB website (trb.org). The revised HSM work plan can be obtained from http://www.wsdot.wa.gov/eesc/design/jsc.
(2.) Review guidance available on the TRB HSM Task Force website, including but not limited to the following:
  • Research acceptance procedures and quality control,
  • Measures for quantifying highway safety effectiveness,
  • Survey of potential users,
  • HSM chapter format, and
  • Guidance on Part IV and V.

(3.) Identify and review literature on the state of the art with regard to the content of Parts IV and V. This includes identification of candidate locations, investigation and analysis of safety conditions at specific sites, selection of countermeasures, economic appraisals of sites under consideration, and prioritization of improvement projects. Include current highway agency practices and procedures related to Parts IV and V and software in current use or under development to implement these procedures. This comprehensive task is intended to provide the knowledge base for Parts IV and V. (4.) Review and revise the annotated outline for Parts IV and V, including the identification of alternative methodologies and processes and the supporting references. (5.) Submit an interim report that summarizes the results of Task 3 and includes the annotated outline developed in Task 4. The interim report shall also identify the prototype chapter that will be developed in Task 6. (6.). Prepare the selected prototype chapter for Part IV or V, for review by the NCHRP and the TRB HSM Task Force. The chapter should include sections with sample calculations and references to software to perform calculations. (7.) Meet with the NCHRP panel to review the Task 6 prototype chapter approximately 2 months after its submittal. After the meeting, submit a revised chapter addressing the review comments and decisions at the meeting. (8.) Develop the remaining chapters. The chapters, as appropriate, should include sections with sample calculations and references to software to perform calculations. (9.) Submit a final report documenting the entire research effort. The final report shall describe how the project was conducted and identify areas for further research that is needed to fill gaps. The report shall include as appendices the chapters for inclusion in the HSM.

Status: The contractor has submitted revised drafts of Chapters 11-16.  The drafts have been provided to the NCHRP Project 17-36 contractor for inclusion in the first edition of the Highway Safety manual.

Product Availability: Draft Chapters 11-16 of the Highway Safety Manual.

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