Proposed Macro-Level Safety Planning Analysis Chapter for the Highway Safety Manual
The Highway Safety Manual (HSM) procedures provide robust methods for conducting site-specific safety analyses known as micro-level analyses. These micro-level analyses can either be in reaction to evaluating alternatives to fix an identified black spot (i.e., reactive), or as part of an entirely new facility planned for an area (i.e., proactive). Micro-level analysis procedures such as the predictive method and Crash Modification Factors presented in the HSM are significant tools that highway agencies are beginning to integrate into their safety management and design procedures and practices. Micro-level analysis tools are suitable for analysis of specific intersections or roadway segments. They make it possible to consider the safety impacts of alternative design features such as the number or type of lanes, shoulder width, or intersection control. In contrast to micro-level analysis procedures for site-specific or corridor situations, macro-level analysis procedures perform analyses on an area-wide basis – entire neighborhoods, cities, and/or regions. Macro-level analysis procedures can be used to incorporate safety prediction into area-wide, long-range transportation system planning, programming, and policy development. The idea of predicting crashes within a given area, such as census tracts or traffic analysis zones (TAZs), allows agencies to identify safety concerns that may not be apparent by examining crash patterns at an intersection or segment scale. This could potentially allow planners to address safety concerns prior to their full materialization. For example, a macro-level model may indicate that changing demographics could result in a sharp uptick in fatalities among the older driver population in a particular section of a city. As a result, agencies could implement wider lane striping and larger sign lettering in that area, or work to improve transit service to older populations. Moreover, macro-level models would help quantify that uptick such that a robust cost benefit analysis could be used to justify one or several of these investments in response to this changing demographic. The ability to analyze and respond to these types of concerns is not currently accounted for in the HSM Predictive Methods. To avoid reactive expensive infrastructure retrofits, macro-level predictive models developed to a standard consistent with the Predictive Method in Part C of the HSM would make it possible to integrate area-wide quantitative safety into planning procedures and programs. The objectives of this research were to develop validated and demonstrated quantitative macro-level safety prediction models and a quantitative safety planning chapter for the AASHTO HSM intended for use by transportation practitioners at all levels. This includes a guidance document on the development and application of these models, methods to integrate the model results into planning procedures, and electronic analysis tools for applying the models in practice. The research results are intended as a new chapter for inclusion in a future edition of the HSM. The results should address a broad range of safety planning level issues related to macro-level models such as, but not limited to, geography, demographics, transportation modes and modal interaction, existing or planned land-use and/or transportation projects, model transferability, calibration needs, and associated data limitations.
Language
- English
Project
- Status: Completed
- Funding: $400000
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Contract Numbers:
Project 17-81
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Sponsor Organizations:
National Cooperative Highway Research Program
Transportation Research Board
500 Fifth Street, NW
Washington, DC United States 20001American Association of State Highway and Transportation Officials (AASHTO)
444 North Capitol Street, NW
Washington, DC United States 20001Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC United States 20590 -
Project Managers:
Jared, David
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Performing Organizations:
Vanasse Hangen Brustlin, Incorporated
333 Fayetteville Street, Suite 1450
Raleigh, NC United States 27601 -
Principal Investigators:
Porter, Richard
- Start Date: 20171026
- Expected Completion Date: 20220930
- Actual Completion Date: 20220930
- Source Data: RiP Project 40846
Subject/Index Terms
- TRT Terms: Crash causes; Crash modification factors; Highway design; Highway safety; Manuals; Metropolitan planning organizations; Safety management; Strategic planning
- Identifier Terms: Highway Safety Manual; Interactive Highway Safety Design Model; Moving Ahead for Progress in the 21st Century Act (MAP-21)
- Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors;
Filing Info
- Accession Number: 01598995
- Record Type: Research project
- Source Agency: Transportation Research Board
- Contract Numbers: Project 17-81
- Files: TRB, RIP
- Created Date: May 12 2016 1:55PM