A Comparison of the VISSIM and CORSIM Traffic Simulation Models

As transportation systems have become more complex and frequently congested, simulation modeling has gained recognition as an effective approach for quantifying traffic operations. Traffic simulation packages like CORSIM and VISSIM can address these types of network issues, and are frequently used as tools for analyzing traffic. However, there is little information available to the analysts applying these models about the most appropriate models to use, or even detailed information about the accuracy of individual models. To address that need, this paper provides a detailed, technical comparison of two popular traffic simulation models (CORSIM and VISSIM). Overall, CORSIM and VISSIM are perhaps more similar than they are different. Both models are designed to model any combination of surface street and freeway facilities, including most signal control and other operational strategies. Both models provide detailed and focused output, both in tabular format and via animated graphics. The main differences between the two models are in vehicle and driver behavior, primarily in the car-following and gap acceptance logic. However, while the nature of these differences is known, the impacts have not been documented. To address these issues, a series of investigations was conducted to compare the two models on specific measures like throughput and LOS. CORSIM and VISSIM give similar results for performance data on the standard measures examined here. At an intersection level, the throughput and LOS predictions from the two models were similar, although the results were different in some cases from the HCM predictions. The biggest difference observed is the variability of the models. Fortunately, this issue is easily addressed by making multiple runs. The comparisons were also good for an analysis of design alternatives on a complex, congested urban street network. Bloomberg and Dale page 2