A Simulation Study for Minimizing Operating Speed Variation of Multilane Highways by Controlling Access

Abstract

Traffic speed is generally considered a main issue in roadway safety. Previous studies show that faster travel is not necessarily associated with an increased risk of being involved in a crash. When vehicles travel at the same speed in the same direction (even high speeds, as on interstates), they are not passing one another and cannot collide as long as they maintain the same speed. Conversely, the frequency of crashes increases when vehicles are traveling at different rates of speed. There is no doubt that the greater speed variation is, the greater the number of interactions among vehicles is, resulting in higher crash potential. This research tries to recognize all primary factors that are associated with speed variation (dispersion) on multilane highways, including roadway access density, which is considered to be the most distinct contributing factor. Additionally, other factors are considered for this purpose, for example: configuration of speed limits, characteristics of traffic volume, geometrics of roadways, driver behavior, environmental factors, etc. A microscopic traffic simulation method based on TSIS (Traffic Software Integrated System) is utilized to exploit mathematical models to quantify the influences of all possible factors on speed variation.