The report describes a series of experiments that were conducted to examine the effectiveness of four-way flashers. Both the disabled vehicle situation and the slow-moving vehicle situation were examined at two- and four-lane locations under both daylight and nighttime conditions. The disabled vehicle tests involved parking a test vehicle (either a car or a tractor-trailer) at the side of the road and monitoring the behavior of drivers. The slow-moving vehicle tests involved introducing a staged slow-moving vehicle (either a car or a tractor-trailer) into the traffic stream and observing the overtaking vehicles. At the disabled vehicle, red and amber four-way flashers as well as flares, reflectorized triangles, headlights, and other situational factors were evaluated. For the slow-moving vehicle tests, the effects of red and amber flashers as well as a 30 and 40 mph (48.3 and 64.4 kph) slow-moving vehicle were examined.

  • Supplemental Notes:
    • See also PB81-217747, Volume 2.
  • Corporate Authors:

    BioTechnology, Incorporated

    Falls Church, VA  United States 

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Knoblauch, R L
    • Tobey, H N
  • Publication Date: 1980-9

Media Info

  • Pagination: 24 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00343562
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA/RD-80-101
  • Contract Numbers: DOT-FH-11-9385
  • Files: NTIS, USDOT
  • Created Date: Oct 28 2003 12:00AM