The Effects of In-Vehicle and Infrastructure-Based Collision Warnings at Signalized Intersections

The potential effectiveness of warnings to drivers of the imminent threat of a collision with a red light violator was evaluated in an experiment that used a driving simulator. Three warnings were tested: (1) an infrastructure-based warning that immediately turned the traffic signal red and activated red wig-wag lights, (2) an in-vehicle warning that consisted of a brake pulse, voice annunciation, and activation of a red dashboard light, and (3) simultaneous activation of both of these warnings. In addition to testing three warnings with different groups of drivers, drivers in each group were exposed to one of three traffic conditions: (1) driving with no other vehicles ahead or behind, (2) following closely to another vehicle, or (3) being closely followed by another vehicle. Individual drivers received only one warning on only one trial. The warning to each driver was given at a point while approaching the intersection where the probability that the driver would stop for an amber change interval was less than 10 percent. Before the warning trial, a series of trials were presented in which the time-to-intersection for amber signal onset was manipulated according to the method of limits to determine the point at which the individual driver would stop in response to the change. All three warnings proved to be effective in delaying drivers’ arrival at the intersection. The simultaneous in-vehicle and infrastructure-based warning was significantly more effective than the other warnings and delayed 95 percent of drivers. The infrastructure only and in-vehicle only warnings delayed 67 and 80 percent of drivers, respectively. The presence of leading or following vehicles had no detectable effect on drivers’ probability of stopping.


  • English

Media Info

  • Media Type: Web
  • Features: Figures; References; Tables;
  • Pagination: 46p

Subject/Index Terms

Filing Info

  • Accession Number: 01154870
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-HRT-09-049
  • Contract Numbers: DTFH61-08-C-00006
  • Files: TRIS, USDOT
  • Created Date: Apr 19 2010 4:09PM