AN EVALUATION OF PERMISSIVE LEFT-TURN PHASING

Abstract

In this study exclusive left-turn phasing was replaced with permissive left-turn phasing at four trial intersections. Intersection delay and accident studies were done before and after the trial installations. Also, a questionnaire was distributed to determine public opinion concerning the signal. Among the results of this study it was found that: permissive phasing at several locations in Lexington, Kentucky resulted in a 50 percent reduction in left-turn delay compared with exclusive phasing (total intersection delay was reduced 24 percent); permissive phasing resulted in an increase in accidents; questionnaire responses showed 90 percent of drivers in the area to be in favor of permissive left-turn phasing; signing to advise motorists of the meaning of permissive phasing is required; and advance publicity should precede installations.