VISSIM is a German microscopic traffic and transit simulation model that is beginning to see increased use within the United States. It is capable of modeling typical passenger vehicles and trucks for freeways and arterials as well as modes of transit such as buses, HOVs, light rail, commuter rail, and heavy rail. In addition, it is also capable of modeling complex traffic control situations, which include: priority and preemption for buses and light rail, all way stop control, and pedestrians. This paper describes the procedures and results of a comparison of the VISSIM (Version 2.91) simulation mode to the better-known CORSIM (Version 4.2) and TRANSYT-7F (Release 8.1) models. In addition, VISSIM's ability to model train operations is also compared to the ARENA model, which simulates train operations. These comparisons were made while modeling the existing traffic condition for the roadway network surrounding the transitway mall in downtown Dallas. This modeling effort was part of two separate projects conducted by Parsons Transportation Group (PTG). The first project was conducted using TRANSYT-7F for the City of Dallas and the second project was conducted for Dallas Area Rapid Transit (DART) using VISSIM and CORSIM. In addition, Manuel Padron & Associates conducted an independent study on train operations for DART using the ARENA software. Ultimately, it is anticipated that the VISSIM model will be used for subsequent analyses of future light rail transit (LRT) expansion in the downtown transitway mall.