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The first phase of the TravTek IVHS experiment will involve the use of in-vehicle Route Guidance Systems (RGS) to determine the best routes through the Greater Orlando Area. These routes will be computed in a distributive fashion based on minute-to-minute travel time updates that are provided by a central Traffic Management Center (TMC). This paper describes the most important traffic engineering aspects of the data fusion, dissemination, and in-vehicle processing of the TravTek system with the intent of demonstrating how the features of each of these steps can be modelled within the TravTek version of the INTEGRATION traffic simulation model. The simulation of these system features is initially intended to assist in developing appropriate TMC and in-vehicle unit system control settings, and to determine the sensitivity of the benefit estimates to alternate parameter settings or system configurations.

The provision of two-way communications between the central traffic control center and all vehicles, which are equipped with route guidance systems (RGS), makes it possible to assemble very efficiently a continuous estimate of the prevailing dynamic or time-varying O-D (Origin-Destination) matrix. This paper describes the mathematics of a four step procedure for developing such a time varying O-D matrix from vehicle probe data and discusses the important statistical limitations of the final O-D estimates. It is shown that, unless there is a very high level of market penetration in the network, the resulting O-D estimate will contain such a high level of statistical uncertainty as to render it of limited practical value.