An Evaluation of Driver Comprehension of Solid Yellow Indications Resulting from Implementation of Flashing Yellow Arrow

National Cooperative Highway Research Program (NCHRP) Report 493 found that a flashing yellow arrow (FYA) permissive indication is well understood by drivers and recommended its application for permissive left-turns. Subsequently, numerous studies have been initiated evaluating the potential impacts associated with the FYA in preparation for its potential inclusion in the Manual on Uniform Traffic Control Devices (MUTCD). In 2006, both the MUTCD and Federal Highway Administration (FHWA) approved the use of the FYA. One question raised is whether the FYA results in a change in drivers’ perceived understanding of the solid (steady) yellow arrow indication (SYA). This research quantified the impact on driver comprehension of the SYA resulting from exposure to and comprehension of the FYA permissive indication. A total of 212 drivers in Madison, WI or Amherst, MA completed a unique sequential experiment including driver’s evaluation of the SYA indication in various scenarios. Among the conclusions were the following: 1);when responding to the SYA indication, only 34 percent of the drivers responded the same before and after exposure to the FYA, however, the changes in responses were cautious in nature, and 2) the distribution of driver responses before and after exposure to the FYA were statistically equivalent in real-world driving scenarios. Therefore, the result show that there was no evidence to suggest that the FYA permissive indication may negatively affect drivers’ understanding of the SYA indication


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; Photos; References;
  • Pagination: 16p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01049276
  • Record Type: Publication
  • Report/Paper Numbers: 07-2293
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 6:59PM