Simulating and Analyzing Incidents Using CORSIM and VISSIM Traffic Simulation Software

A key component in measuring the performance of a transportation network using simulation software involves simulating incidents and studying their impacts on system performance. Incidents on a freeway influence traffic behavior on not only the lane on which it occurred but also show considerable effect on the traffic of the adjacent lanes and the secondary road network. The capabilities afforded by various traffic simulation software to create and analyze incident vary significantly. The objective of this paper is to explore the capabilities of the CORSIM and VISSIM traffic simulation software to simulate and analyze incidents on a basic freeway segment. The study showed that incidents could be simulated more effectively using CORSIM when compared to VISSIM. The advantage in CORSIM lies with the comprehensive freeway incident simulation procedure, which is available as a part of the FRESIM module. The user can control the incident by specifying various factors such as the longitudinal position of a freeway link at which the incident has occurred, distance over which the effects last and the duration of the incident that influence the incident. The percentage of the traffic affected by the incident on the lane adjacent to the incident lane can be pre-established. This is used to reproduce real time situations where the traffic is affected by the adjacent lane traffic behavior. VISSIM has no special provision to simulate freeway incidents and/or work-zones that close a lane. However, incidents can be created on a freeway lane and its effects studied by exploring the capabilities of VISSIM by simulating a bus to stop for a stipulated amount of time. But, VISSIM does not have the ability to specify blockages or "rubber necking" on a lane specific basis or to simulate short-term and long-term interruptions to traffic (known as events) as can be done using CORSIM software. Data from the Las Vegas metropolitan area are used to compare the capabilities and performance of CORSIM and VISSIM simulation software.