The analysis of safety impacts of “Near-Site” traffic signals

Abstract

Many approaches have been performed to reduce traffic accidents at signalized urban intersections in Korea. Among them installing red-light running cameras have been the most popular and simplest approach. Recently, on the other hand, engineering approaches have been tried and as a result, some provinces in Korea have started to install “near-site” traffic signals. Near-site signals are installed before crossing the intersection, aiming to reduce traffic violations and accidents at intersections. This new approach, however, has been performed without any in depth studies. Thus, this research attempts to verify the impact of near-site signals on traffic safety based on collected field data of drivers’ behaviors. Accident rates at signalized intersections with near-site traffic signals have been collected to study the direct effects of near-site signals. This study also collects violation rates of stop lines and traffic signals, and approach speed to examine the rate of reduction of possible risks at intersections. A simple comparison method has been applied. By comparing violation rates, approach speed, and accident rates, while excluding adjustment periods, this research finds that intersections with near-site signals can enhance traffic safety. Furthermore, this research suggests near-site signals should be installed at intersections that has the number of intersecting lanes are less than 6 lanes to maximize the impact on traffic safety.