The problem of the estimation or updating of origin/destination (O/D) matrices from traffic counts both for road and transit networks have been analysed and many methods have been presented in literature during the last 20 years; they can be mainly classified in static and dynamic estimation methods. In the sphere of low-frequency (extraurban) uncongested transit networks, this paper presents a methodology to estimate dynamic (time-varying) transit O/D matrices from time-varying traffic counts using a Generalised Least Squares estimator and a schedule-based dynamic path choice model of stochastic type. This methodology is actually used in the Decision Support System of the Italian Railways to estimate the railway O/D matrices at national scale. Section 2 defines the general formulation of the problem. Section 3 describes the schedule-based dynamic approach in transit modelling which is used in the estimation method presented in section 4 in order to estimate a time-varying O/D matrix for extraurban transit networks. Finally, section 5 reports an application example to a realistically-sized transit network.
Samenvatting