A Study of Collisions with Lead Versus Lag Left-Turn Phasing: Additional Data and Analyses

This paper reports on a study comparing 8 years of collision data for intersections with leading and lagging left-turn arrow operations in two Arizona cities. Collision experience is compared at 13 intersections with lagging left-turn arrows and 9 intersections with leading left-turn arrows. Results showed that lagging left-turn arrows had a statistically significant lower collision rate than leading left-turn arrows for all collisions, collisions involving left-turning vehicles and collisions involving left-turning vehicles with opposing through vehicles. There was no statistically significant difference between lagging left-turn arrow operation and leading left-turn arrow operation in the rate of collisions that did not involve left-turn vehicles.


  • English

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  • Accession Number: 01055246
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 21 2007 1:17AM