SPR 771 Safety Analysis of Highway Curves Where Crashes Occur in South Carolina

A recent study conducted by this research team of over 900 2019 South Carolina fatal crashes showed that nearly 20 percent occurred on highway horizontal curves. The study further identified that 25% of the curves where these crashes occurred may have had design speeds less than the posted speed limit and 47% of the curves have a design speed less than 5 mph above the speed limit. Prior research on operating speeds indicates that drivers tend to drive at least 7-10 mph above the posted speed limit. With design speeds below or right at the posted speed limit, excess speed of any level can become problematic. This research focuses on a detailed analysis of curves where vehicle crashes occur in South Carolina compared to similar radii highway curves that have a significantly lower crash incidence. The existing inventory of circular curves along with crash data will need to be analyzed to identify trends and the effectiveness of countermeasures. There are some known issues with the Rieker highway curve inventory. Some of these issues will be corrected as part of this research. These issues include locations identified as curves that are actually intersections and correctness of attributes essential for safety analysis. The Manual on Uniform Traffic Control Devices (MUTCD) compliance issues related to horizontal alignment warning information is a concern of South Carolina Department of Transportation (SCDOT). This research will help to address that concern.


    • English


    • Status: Active
    • Funding: $295563
    • Sponsor Organizations:

      South Carolina Department of Transportation

      955 Park Street
      P.O. Box 191
      Columbia, SC  United States  29202-0191
    • Principal Investigators:

      Sarasua, Wayne

    • Start Date: 20240201
    • Expected Completion Date: 20260131
    • Actual Completion Date: 0

    Subject/Index Terms

    Filing Info

    • Accession Number: 01906722
    • Record Type: Research project
    • Source Agency: South Carolina Department of Transportation
    • Files: RIP, STATEDOT
    • Created Date: Feb 1 2024 9:47AM