Simulating the Effects of Type and Spacing of Traffic Calming Measures on Urban Road Capacity

One of the major reasons for accidents is speed. Inappropriate speed has been identified as the most important causal factor for serious traffic accidents. Traffic calming measures (TCMs) are engineering measures that are widely implemented to improve road safety by considerably reducing vehicle speed. TCMs have been widely used in urban areas to reduce vehicle flow rates and especially speed, and hence, to bring down the number and severity of traffic accidents. Despite numerous studies in literature, little attention has been paid to the effects of speed reduction using TCMs on network capacity regarding the main traffic operation parameters, including delay time, average speed of vehicles passing through the network, and vehicle fuel consumption. In response to this need, in this study drivers’ behavior in the presence of TCMs, based on different types and spacing of TCMs, was investigated using Aimsun software. For this purpose, the effects of number of TCMs and their locations in the network were simulated in various scenarios and their capacity and operation performance parameters on urban roads were calculated accordingly. Consequently, according to the technical criteria, the scenarios in which the TCMs were implemented presented a better design quality. On the other hand, according to the results obtained in the different scenarios of this research, delay time and average fuel consumption of vehicles substantially increased while the average speed was reduced. It was found that TCMs have a direct effect on the network capacity and changing in the number and location of measures can change network capacity.