Right turn Adjustment Factor for Permitted Phase

Abstract

Protected phas plan is commonly used for most intersections in Thailand to ensure safety on the intersections. However, the use protected phase increases vehicle delay and wastes of green light than necessary especially on an intersection with low traffic volume. In this regard, studies conducted to determine the impact of a right-turn vehicle during the permitted phase have not been found. Therefore, this study will collect and analyze data to find the right turn adjustment factor for permitted phase. This adjustment factor could be used in the design of traffic signal to be suitable for intersections with low traffic volumes.