Warrants for the installation of left-turn phasing were developed. A review of literature was conducted along with a survey of the policies of other states. Field data of delays and conflicts were taken before and after installation of exclusive left-turn signalization. Left- turn delay studies were conducted at intersections with varying volume conditions. Analysis of the effect on accidents of adding a left-turn phase were made. The relationship between left-turn accidents and conflicts was investigated. Other types of analysis concerning gap acceptance, computer simulation, capacity, and benefit-cost ratios were also performed. It was found that exclusive left-turn phasing significantly reduced left-turn acciddents and conflicts. Left-turn delay was only reduced during periods of heavy traffic flow. Warrants were developed dealing with the following four general areas: 1. accident experience, 2. delay, 3. volumes, and 4. traffic conflicts.

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 30 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00141847
  • Record Type: Publication
  • Report/Paper Numbers: Research Rpt 456, Interim Report
  • Contract Numbers: KYP-75-70
  • Created Date: Jan 16 2002 12:00AM