The Generation of Synthetic O-D Demands from Real-Time Vehicle Probe Data: Potential and Limitations

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. Consequently, it is anticipated that the resulting O-D estimate will even in the long term not be unsuitable to be utilized on its own, and that instead this estimate will always need to be further processed as a seed solution matrix for a subsequent dynamic synthetic O-D generation analysis.