EFFECT OF FREEWAY RAMP METERING ON ACCIDENTS: THE ARIZONA EXPERIENCE

An evaluation was conducted that compared accident frequency 3 years before and 3 years after the installation of ramp metering at nine locations on the Superstition Freeway. Ramp metering at the nine locations is in operation only during selected hours of the day. Therefore, it was possible to compare changes in accident frequency during periods of the day when ramp metering is in operation with periods of the day when ramp metering is not in operation. Rear-end and sideswipe accidents on the freeway mainline during the periods when ramp metering is in operation declined 10%, while accidents during the periods when ramp metering is not in operation increased 33%. Rear-end accidents on the entrance ramps during the periods when ramp metering is in operation increased substantially (from 2 to 82). This large increase was attributed to the vehicles now being required to stop on the entrance ramp. In addition, an increase in these accidents during the periods of the day when ramp metering is not in operation was also observed (from 34 to 76). It appears that some of this increase was due to vehicles that slowed or stopped unexpectedly at the traffic signal during those periods even though the metering was not in operation.

  • Availability:
  • Corporate Authors:

    Institute of Transportation Engineers (ITE)

    Washington, DC  United States 
  • Authors:
    • Cleavenger, D K
    • Upchurch, J
  • Publication Date: 1999-8

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00768882
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 16 1999 12:00AM