OFF-RAMP SURVEILLANCE

The report describes the surveillance of each off-ramp in California using a counter and camera developed by California Department of Transportation engineers. These counters used a pneumatic road tube to detect the vehicle, electronic circuitry to identify the wrong-way move, and a small single frame camera to verify the wrong-way move. Wrong-way entries into off-ramps were found to be extremely high at some locations. Some as high 50 to 60 entries per month. Successful reductions in wrong-way entries were accomplished by placing the DO NOT ENTER wrong-way signs at the decision point of each likely wrong-way approach and lowering them to 2 feet (0.6 m) above the pavement. A variety of unusual problem ramps and techniques were described in this report. Various automatic wrong-way signs and lighted freeway entrance signs were tried. Most were helpful where the standard DO NOT ENTER and FREEWAY ENTRANCE signs weren't enough. The most promising development is the wrong-way pavement lights. These are a row of red lights embedded in the pavement across the off-ramp. They are placed 200-300 (61.0-91.5 m) feet from the intersection at the secondary wrong-way sign locations. Evaluation of 10 existing installations is in progress. A 16 mm movie film was made which shows five different techniques: internally illuminated freeway entrance signs, pathfinder signs, pavement marker derailer, overhead internally illuminated wrong-way sign and pavement lights.

  • Corporate Authors:

    California Department of Transportation

    1120 N Street
    Sacramento, CA  United States  95814

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Rinde, E A
  • Publication Date: 1978-8

Media Info

  • Pagination: 128 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00304676
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA-RD-79-T0334 Final Rpt., 623124
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Jan 15 1980 12:00AM