MITSIM maintains two sets of travel time information: historical and real-time. Real-time link travel times are updated periodical or when information is received from TMS. The updated travel times are ``transmitted'' to the vehicles equipped with on-board route guidance devices when vehicles enter the range of a communication beacon. Upon receiving the new information, guided drivers select their routes based on the updated travel times. Any vehicle may respond to VMS according to a pre-specified compliance rate.
Route choice models are used to capture drivers' route choice decisions and response to traffic information. Regarding access to in-vehicle information, two driver groups are assumed: informed and uninformed drivers. Drivers may have either predefined or dynamically computed paths. Depending on the situation, a route choice model or a route switching model may be used to update a vehicle's paths.