Extending the Sydney Strategic Model to represent toll road and park-and-ride choices

The Sydney Strategic Transport Model (STM) has recently been re-estimated using more recent household travel survey data, a more detailed zoning system, an extended geographic scope and extensions to the model scope. This paper focuses on the two key extensions to the model scope, both of which involved adding additional choice decisions to the mode destination model structure. First, the choice to travel by tolled or untolled routes was modelled as a nest beneath car driver, with separate alternatives for tolled and untolled routes. Separate assignments were made to provide the level of service for these two alternatives, and these are discussed in the paper. A key finding from the runs was that long-distance travellers were much more likely to choose to use toll roads, even for purposes like commute where willingness to pay was segmented by income. Second, park-and-ride was modelled by explicitly representing different access mode options to train (park-and-ride, kiss-and-ride, other), and for car access choice of station. The paper will report on specific adjustments that were made to the model in order that the observed variation in observed access mode shares with distance to stations was replicated in base year model predictions. The paper discusses the estimation of model structure. The following choices are simultaneously represented in the nesting structure: • main mode • public transport mode • train transport access mode • train station • destination • toll road