Freeway Safety Evaluation: A Quantitative Approach Using Highway Safety Manual to Informed Decisions

Document Type

Conference Proceeding

Publication Date



design, highways, operations and traffic management, planning and forecasting, safety and human factors


Performance-based design in the form of operation and safety in the freeway system plays a significant role in alternative evaluation process. Moreover, performance-based design consistent with Highway Safety Manual is getting more accepted and adopted by the highway agency since it sets specific goals in meeting safety targets that lead to meet performance criteria. Nebraska Department of Roads (NDOR) sets targets by using the systematic safety assessment on design modifications. The application of Highway Safety Manual (HSM) in the safety assessment of freeway alternatives focusing on Metropolitan Travel Improvement Study (MTIS) provides a new direction for making informed decisions at the agency level. With that in mind, this study was conducted with the objectives to perform: (1) safety performance evaluation of alternatives in the MTIS by applying Enhanced Interchange and Freeway Safety Analysis Tool (ISATe); (2) safety performance evaluation of design exceptions; and (3) qualitative safety performance evaluation of sub-options as part of sensitivity analysis for design year 2040. This paper focuses on a performance-based approach to compare safety performance of alternatives and provides information to assist safety professionals, designers, planners, and policy makers at state and local levels in making informed decisions. Finally, this study highlights some of the challenges of using predictive tool recommend by HSM in real applications.

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Citation / Publisher Attribution

Presented at the Transportation Research Board 97th Annual Meeting on January, 2018 in Washington D.C.