Measuring Intersection Safety

This project proposes to measure the time when every vehicle enters an intersection, together with its speed and the signal phase. These data will be analyzed to score how unsafe the vehicle's entrance to the intersection is, e.g. score is 0 if the vehicle enters during green below the speed limit, or 1 if the vehicle enters during amber or red or faster than the speed limit. An aggregation of the score will create an intersection safety index (ISI). Changes in ISI over time will be correlated with traffic conditions and with the intersection signal control plan, to tease out the impact of the latter on ISI. There are two tasks. The first is to design modifications to 170 controllers to extract signal phase and time-synchronize it with the detector measurements of each vehicle's speed. The second task is to collect and analyze data at several intersections. The ISI technique differs from the three approaches to intersection safety: the Highway Safety Manual (HSM) intersection design guidelines based on an assessment of crash statistics; the Traffic Conflict Technique (TCT) using trained observers to watch an intersection and assess the occurrence of near-accident events; and RITA/CICAS initiative to assist drivers to improve safety.


    • English


    • Status: Active
    • Contract Numbers:


    • Sponsor Organizations:

      California Department of Transportation

      1227 O Street
      Sacramento, CA  USA  95843

      Department of Transportation

      Research and Special Programs Administration
      1200 New Jersey Avenue, SE
      Washington, DC    20590
    • Performing Organizations:

      University of California Transportation Center (UCTC)

      University of California, Berkeley
      2614 Dwight Way, 2nd Floor
      Berkeley, CA  USA  94720-1782

      University of California, Berkeley

      Transportation Center
      2614 Dwight Way, 2nd Floor
      Berkely, CA  USA  94720-1782
    • Principal Investigators:

      Varaiya, Pravin

    • Start Date: 20100801
    • Source Data: RiP Project 28002

    Subject/Index Terms

    Filing Info

    • Accession Number: 01463718
    • Record Type: Research project
    • Source Agency: University of California Transportation Center (UCTC)
    • Contract Numbers: 15833JEVA1
    • Files: UTC, RiP, USDOT, STATEDOT
    • Created Date: Jan 3 2013 2:29PM