A modelling framework is developed to analyze the effect of in-vehicle real time information strategies on the performance of a congested traffic communing corridor. The framework consists of a special-purpose simulation component and a user decisions component that determines users' responses to the supplied information. The user decisions component is microscopic and determines individual commuters' route switching, at any node of the network, as a function of the supplied information. The traffic simulation component moves vehicles in bundles or macroparticles at the prevailing local speeds, as determined by macroscopic traffic relations. The framework allows the investigation of system performance under alternative behavioral response mechanisms, as well as under different information strategies. Results are presented for simulation experiments in a commuting corridor with a special network structure that simplifies the network computations. The results illustrate the effect of the fraction of users equipped with in-vehicle navigation systems on overall system performance. In addition, alternative assumptions on user response reflecting varying degrees of optimizing behavior are explored. The modelling framework is shown to provide a useful approach for addressing key questions of interest in the design of real time in-vehicle information system.