Investigation of Rural/Suburban High-Speed Multilane Roundabouts

The proposed research is focused on investigating two issues related to multilane roundabouts on high-speed highways (speed limit 50 mph or greater) in rural and suburban areas. The first is the tradeoff between converting a traditional stop controlled or signalized intersection to a multilane roundabout on high-speed state highways while the second is the safety of newly constructed high-speed multilane roundabouts in rural and suburban areas. Guidance on design of roundabouts is available in the Nebraska Department of Roads (NDOR) Roadway Design Manual (Chapter 4) and in the National Cooperative Highway Research Program (NCHRP) Report 672. The latter document also provides information on the safety benefits of converting traditional intersections to roundabouts. However, most of the available information deals with urban or suburban locations and with single-lane roundabouts. There is no information available on the benefits of converting rural intersections on high-speed highways to multilane roundabouts. Availability of such information would be useful to NDOR staff when contemplating conversions of intersections to roundabouts. Many single lane roundabouts have been constructed in Nebraska with favorable safety results and several multilane roundabouts on high-speed Nebraska state highways are planned for construction in the near future. However, there are questions about the safety performance of multilane roundabouts constructed on high-speed facilities. The NCHRP 672 report notes that most multilane roundabouts experience increased safety benefits over conventional intersections; however some state transportation agencies experienced an increase in crashes immediately after converting a conventional intersection to a multilane roundabout. In these instances, the subject roundabout was followed by negative publicity and public opinion (http://www.insurancejournal.com/news/east/2011/06/28/204259.htm). A recent City of Lincoln experience with the newly constructed multilane roundabout at North 14th and Superior streets has also not been favorable due to a spate of crashes after completion of construction. Therefore, one of the aims in this research is to avoid safety issues that other agencies experienced with newly constructed roundabouts in Nebraska and thereby mitigate possible negative publicity and public opinion about multilane roundabouts. Overall, this research is aimed at investigating the tradeoffs between traditional intersections and roundabouts on high-speed state highways located in rural and suburban areas and exploring safety issues associated with multilane roundabouts on high-speed facilities located in rural and suburban areas. The following NDOR projects could potentially benefit from this research: Kearney East Bypass, 11th St. to 56th St.; Norfolk intersection of US-275 and N-35, and Norfolk intersection of 37th St. and US-275. These projects are planned for construction during the 2013-2015 periods.

    Language

    • English

    Project

    • Status: Completed
    • Funding: $123647.00
    • Contract Numbers:

      SPR-P1(14) M008

    • Sponsor Organizations:

      Federal Highway Administration

      Federal Lands Highway Division, 555 Zang Street
      Lakewood, CO  United States  80228

      Nebraska Department of Roads

      1500 Highway 2
      Lincoln, NE  United States  68502
    • Performing Organizations:

      University of Nebraska, Lincoln

      527 Nebraska Hall
      Lincoln, NE  United States  68588-0529
    • Principal Investigators:

      Khattak, Aemal

    • Start Date: 20130701
    • Expected Completion Date: 0
    • Actual Completion Date: 20141231
    • Source Data: RiP Project 34274

    Subject/Index Terms

    Filing Info

    • Accession Number: 01572296
    • Record Type: Research project
    • Source Agency: Nebraska Department of Roads
    • Contract Numbers: SPR-P1(14) M008
    • Files: RiP, STATEDOT
    • Created Date: Aug 5 2015 1:00AM