Safety evaluation of a flashing-green light in a traffic signal

Abstract

This paper presents an analysis of the conditions at an intersection during the change of the green light to amber and red. On the basis of engineering assumptions, two zones - a dilemma zone and option zone - are defined. An indecision zone, based on behavioral considerations, is also defined. In consideration of these zones, the paper evaluates a particular 'end of green, warning of a three-second flashing green just prior to the amber light. It is shown that flashing green light increases the length of the indecision zone and consequently increases the probability for rear-end collisions. This conclusion is supported by accident data.