Analysis of Traffic Operations at All-Way Stop-Controlled Intersections by Simulation

All-way stop-controlled (AWSC) intersections are one of the common intersection types in the United States. Although significant research has been completed on signalized intersections and two-way stop-controlled intersections, a limited number of studies have been made of traffic operations at AWSC intersections. In addition, although a general analytical procedure now exists for AWSC intersections, it is not capable of handling the wide variety of conditions typically faced by the practicing traffic engineer. Further, it may not be computationally possible for an analytical model to handle the large number of vehicle interaction combinations that exist at AWSC intersections. This study presents a new AWSC simulation model and some of the results from that simulation. The model was tested against the field data collected during NCHRP Project 3-46, Capacity and Level of Service at Unsignalized Intersections. The model can be used to predict vehicle delay, queue length, and saturation headways, which have shown good correlation with the field data. The simulation model predicted the same level of service for about 66 percent of the cases tested, and for 100 percent of the cases the model predicted level of service within one level difference.