Safety of U-Turns at Unsignalized Median Openings

Many state and local transportation agencies are considering installing nontraversable medians on multilane highways. Business and property owners often resist these improvements. One of the arguments made is that the number of U-turning vehicles will increase. However, the impact of an increase in U-turns on the safety of the road is not clear. Studies attributing safety gains to a nontraversable median have not focused on the specific situation at the median opening, either isolated or at an intersection, where U-turns occur. After a nontraversable median has been installed, agencies are often approached by abutting property owners who desire a new median opening. Additional information would be helpful in reviewing these requests, determining if an opening should be allowed, and developing a design that does not unduly impact the safety or operation of the road. There is a wide variety of designs for nontraversable medians. A thorough review of the safety and operational impacts of the various designs would be beneficial, both in setting design policy and in project-level design. The objectives of this research are to document the safety impacts of U-turns at unsignalized median openings and to develop a guide for the use, location, and design of unsignalized median openings for U-turns.


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  • Status: Completed
  • Funding: $320000
  • Contract Numbers:

    Project 17-21

  • Sponsor Organizations:

    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

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Derr, B

  • Performing Organizations:

    Midwest Research Institute

    425 Volker Boulevard
    Kansas City, MO  United States  64110-2299
  • Principal Investigators:

    Potts, Ingrid

  • Start Date: 20001106
  • Expected Completion Date: 20040130
  • Actual Completion Date: 20040130
  • Source Data: RiP Project 5228

Subject/Index Terms

Filing Info

  • Accession Number: 01459537
  • Record Type: Research project
  • Source Agency: National Cooperative Highway Research Program
  • Contract Numbers: Project 17-21
  • Files: RiP, USDOT
  • Created Date: Jan 3 2013 1:05PM