In this case study, a VISSIM microscopic traffic simulation was integrated with a DriveSafety driving simulation using the High Level Architecture. The goal was to integrate the two disparate, simulations such that a driver controlling a vehicle in the driving simulation would interact with other vehicles controlled by the traffic simulation. This level of interaction requires a two-way real time exchange of information between the simulations. Because of issues concerning the import/export capabilities of the simulation programs, and inconsistencies in model representation and meaning of data, as well as the delays in the transfer of data, only a one-way communication flow was established. Vehicle location data was sent from the traffic simulation to the driving simulation to create vehicles and control their movements; however the driving simulation maintained primary control over the vehicles.