Intelligent Dilemma Zone Protection System at High-Speed Intersections

Drivers’ actions in an intersection’s dilemma zone – the area where the decision to stop at a yellow light or continue through it is not clear-cut – can lead to side-angle and rear-end crashes. In Maryland, researchers developed an intelligent dilemma zone protection system (DZPS) that is reducing these crashes by anticipating drivers’ decisions and responding. The DPZS system was deployed at two high-speed rural intersections (US 40@Western Maryland Parkway and MD 213@Williams/Locust Point Road), and it has three components: (1) two wide-range sensors to track the speeds and locations of all vehicles within the identified dilemma zones; (2) software to predict the response of drivers during the yellow phase and to activate the all-red extension function if needed; and (3) a web-based module for responsible engineers/technicians to monitor the system’s performance from a control center. Measured benefits of DZPS include a 30 to 40 percent reduction in dilemma zone length and fewer vehicles approaching the intersection at speeds greater than the posted speed limit. The all-red extensions have helped prevent crashes between through traffic and vehicles entering the intersection from the cross street.

  • Record URL:
  • Corporate Authors:

    University of Maryland, College Park

    Department of Civil and Environmental Engineering
    College Park, MD  United States  20742

    Maryland Department of Transportation

    State Highway Administration, 707 N Calvert Street
    Baltimore, MD  United States  21202
  • Authors:
    • Park, Sung Yoon
    • Chang, Gang-Len
  • Publication Date: 2017-7-7


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 88p

Subject/Index Terms

Filing Info

  • Accession Number: 01643745
  • Record Type: Publication
  • Report/Paper Numbers: MD-17-SHA/UM/3-32
  • Contract Numbers: SP409B4K
  • Created Date: Aug 17 2017 5:09PM