Additional Estimation of the Sydney Strategic Travel Model

The Sydney Strategic Travel Model (STM) was originally developed between 1999 and 2002, and informs long term transport planning, policy development and infrastructure assessment across the Greater Sydney area. During 2009 and 2010, the individual demand models that comprise the STM were re-estimated to use more recent survey data, the geographic scope of the model was extended, and additional model components were incorporated to predict demand for toll roads and park-and-ride schemes.

During 2010 and 2011, three parallel projects were undertaken to implement the new models in the STM, and the predictions of the new model implementation for commuting travel were validated in detail. While the validation exercise demonstrated that the overall performance of the new model was good compared to observed travel data, it also identified a number of specific areas that could be improved.

This report describes additional model estimation work that has been undertaken to further improve the commute mode-destination model. The improvements are an extension of the scope of the model to represent separate walk and bus access modes to train, changes to the model specification to predict higher walk usage in high density areas close to the Central Business District, and investigations of the impact of new terms for car driver. Changing the commute mode-destination model necessitated changes to other components of the forecasting system and these changes are documented in the report.