REVIEW AND EVALUATION OF FACTORS THAT AFFECT THE FREQUENCY OF RED-LIGHT-RUNNING

Red-light-running is a significant problem throughout the United States and Texas. It continues to increase in frequency each year at most intersections and it leads to frequent and severe crashes. Engineering countermeasures represent an attractive means of combating the red-light-running problem because they are intended to help drivers be lawful and they are not punitive (unlike enforcement). The objective of this research project is to describe how traffic engineering countermeasures can be used to minimize the frequency of red-light-running and associated crashes at intersections. This report describes findings from the first year of a two-year project. During the first year, studies were conducted of red-light-running frequency and crash rates at 12 intersection approaches in three Texas cities. The findings from these studies indicate that the frequency of red-light-running increases in a predictable way with increasing approach volume, increasing heavy-vehicle percentage, and shorter yellow interval durations. The crash data analyses indicate that right-angle crashes increase exponentially with an increasing frequency of red-light-running. Models for computing an intersection approach's red-light-running frequency and related crash rate are described.