DO INCIDENT WARNING SYSTEMS IMPROVE SAFETY?

The question of the title is answered by results from a traffic safety evaluation of incident warning systems (IWS). A review of accidents on the IWS sections showed that a large proportion of accidents at the sites were relevant for IWS, but there were considerable differences between the accident patterns at each site. The IWS based on roadside light poles caused a reduction of driving speeds, especially the highest ones, and thereby stabilized the traffic flow. Most of the disturbances and conflicts were connected to overtaking situations. The number of overtakings and related disturbances had decreased after the implementation of the IWS. The speed changes indicated a reduction in accident risks, most likely of the magnitude of 10-15%. According to a stimulator study, all IWS systems investigated made the drivers slow down and speeded up the drivers' response to the incidents. The content and coding of messages affected driver behavior, especially via the action recommendations displayed. The level of detail in the messages, however, had no effect on the variation of behavior. There were large individual differences between drivers in reacting to IWS messages. Some drivers will obey a message to a rather high degree, while another group will rely more on their own judgement than on the IWS. Earlier accident studies have usually shown accident reductions on the IWS equipped motorway sections. The whole range of the effect on the total number of injury accidents was from -35% to +9%. The effects were more beneficial on secondary accidents.

• Supplemental Notes:
  • Full conference proceedings available only on CD.
• Corporate Authors:

  ITS America

  1100 17th Street, NW, 12th Floor
  Washington, DC  United States  20036
• Authors:
  • KULMALA, R
  • Franzen, S
• Conference:
  • Intelligent Transportation: Realizing the Future. Abstracts of the Third World Congress on Intelligent Transport Systems
  • Location: Orlando, Florida
  • Date: 1996-10-14 to 1996-10-18
• Publication Date: 1996

Language

• English

Media Info

• Pagination: n.p.

Subject/Index Terms

• TRT Terms: Automobile drivers; Behavior; Drivers; Intelligent transportation systems; Messages (Communications); Motor vehicles; Risk assessment; Speed; Traffic crashes; Traffic incidents; Traffic safety; Warning systems
• Uncontrolled Terms: Incidents; Messages
• Old TRIS Terms: Accident risks
• Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors; I83: Accidents and the Human Factor; I85: Safety Devices used in Transport Infrastructure;

Filing Info

• Accession Number: 00741328
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 7 1997 12:00AM