Developing Crash Modification Factors for Alternative Intersections

Alternative intersection designs, including Displaced Left Turn (DLT), Median U-Turn (MUT), and Restricted Crossing U-Turn (RCUT), have been implemented in the United States to reduce congestion. The reduction in the number of traffic signal phases and conflict points at these intersections results in improved traffic operations and safety. Various research has been conducted to develop crash modification factors (CMFs) for typical intersections as well as conversion of traditional intersections to roundabouts. Additional studies have been conducted to evaluate the safety benefit of different intersection configurations. In the past 10 years, the number alternative intersections have increased substantially in the U.S. The operational improvements of the alternative intersections over conventional intersections have been proven. The total number of conflict points for alternative intersections are lower than traditional intersections, and, as a result, offer safety advantages over conventional intersections. Studies show significantly lower crash rates with MUTs and RCUTs for both corridor-wide and intersection related data. Lower crash rates for DLT’s are also supported by intersection data following DLT installation; however, there are safety concerns, especially for older drivers and those unfamiliar with alternative intersections. The objective of this research is to develop CMFs for alternative intersection types, to include but not be limited to DLT, MUT, and RCUT configurations, and hence a tool for estimating crashes with and without alternative intersections. The research would inform engineers, transportation agencies, and the public of the safety benefits of alternative intersections by quantifying the reduction in crash frequency and severity resulting from conversion of traditional signalized intersections to DLT, MUT, RCUT, or other alternative configuration. Ultimately, it would help transportation professionals evaluate alternative intersection strategies in terms of safety benefits. The estimation/evaluation tool could be included in Highway Safety Manual, state DOT manuals and guidelines, and in the CMF Clearinghouse, and it could support progress towards Vision Zero goals across the U.S.

Language

  • English

Project

  • Status: Proposed
  • Funding: $600000
  • Contract Numbers:

    Project 17-108

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Jared, David

  • Start Date: 20210528
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01773425
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 17-108
  • Files: TRB, RIP
  • Created Date: May 24 2021 3:14PM