There is a significant opportunity to improve the explicit role of highway safety in making decisions on roadway design and operations. Improved, low-cost technologies have encouraged many state departments of transportation and other agencies to develop systems that deliver better safety information. In addition, there has been a parallel advancement in the science of safety impact prediction. Better understanding of the statistical nature of crashes, coupled with new analytical tools, makes it possible to produce more valid estimates of the effect of geometric and operational changes on the frequency and severity of crashes.
The American Association of State Highway And Transportation Officials has developed a strategic highway safety plan, with 22 emphasis areas, containing a number of countermeasures designed to quickly reduce fatalities on our nation's roads. Two of the initiatives address safety information and management of the highway safety system. A key strategy for these initiatives involves improving safety information systems for better decision support.
Furthermore, the move toward "context-sensitive design" approaches has put additional pressure on state and other agencies to develop the means and tools for making design decisions that may involve exceptions to existing criteria. The safety impacts of such decisions should be explicitly considered.
Recent legislative requirements for improving safety data and the use of safety as an explicit criterion in planning and designing transport facilities have created needs within many agencies for improved tools and techniques for safety analysis. Although there have been substantial investments in research and development on highway safety related to the roadway environment (e.g., Federal Highway Administration's [FHWA] program to develop the Interactive Highway Safety Design Model), there is no commonly accepted, fully integrated approach for safety analysis of designs. Hence, safety may not be incorporated in the most effective manner.
In December 1999, a workshop was held, under sponsorship of eight Transportation Research Board (TRB) committees and funded by FHWA, for the purpose of determining the need for, nature of, and feasibility of producing a Highway Safety Manual
(HSM). A group of about 25 researchers and practitioners participated in the workshop and concluded that there was definitely a need for such a technology transfer activity and that work should begin as soon as possible on the development of an HSM. The results of the workshop will be documented in a TRB research circular.
The HSM should have similar attributes to the Highway Capacity Manual.
The purpose of an HSM will be to provide the best factual information and tools, in a useful and widely accepted form, to facilitate roadway design and operational decisions based upon explicit consideration of their safety consequences.
The objectives of this project are to (1) complete a scoping study that details the effort required to produce the first edition of the Highway Safety Manual
(HCM) and (2) develop a prototype chapter that incorporates the analytical procedure that is being developed by the FHWA for safety estimation on rural two-lane highways.
To accomplish the objectives, the following tasks are envisioned: (1) Critically review the conceptual framework outlined in the TRB Research Circular, and, based on past research and current practice, develop a detailed outline for the first edition of the Highway Safety Manual. (2) Submit the outline for review by the NCHRP project panel and the TRB Joint Subcommittee on the HSM. (3) Revise the outline, and prepare a detailed work plan for developing the actual HSM. The work plan shall define the available knowledge upon which to base the HSM and the effort required to distill that knowledge into the HSM. It shall also estimate the staffing, time, and other resource requirements necessary to develop the HSM. (4) Identify critical elements for inclusion in a prototype chapter and potential methods for presentation. (5) Prepare a detailed annotated outline of a prototype chapter, defining both technical content and presentation methods. (6) Submit the prototype chapter outline for review by the NCHRP panel and the TRB Joint Subcommittee on the HSM. (7) Based on the results of the review, develop the draft prototype chapter including proposed interactive tools. (8) Submit an interim report documenting the results of Tasks 3 and 7. (9) Meet in Washington, D.C., with the NCHRP panel and the Joint Subcommittee to review the Task 8 interim report approximately 1 month after its submittal. (10) Revise the interim report based on decisions made at the Task 9 meeting. (11) Submit a final report documenting the entire research effort. The final report shall describe how the project was conducted and also incorporate the revised interim report.
This project has been completed.
Product Availability: NCHRP Research Results Digest 286
, Development of a Highway Safety Manual, summarizes the research conducted under this project. The final report is available online as NCHRP Web Document 62