Stage 2: Recalibrating Adelaide’s strategic transport model
This study will develop a robust, efficient and cost-effective methodology for the calibration of the Strategic Adelaide Model (SAM) that does not rely on primary data collection methods.
In particular, the study will use household travel diary datasets collected in other jurisdictions within Australia to update SAM model parameters, augmented wherever possible with additional information available through the Census and other datasets regularly collected by the Australian Bureau of Statistics (ABS).
It will develop a data averaging procedure that allows our methodology to be extrapolated to contexts that differ significantly from where the primary data was collected and offers a viable approach for the development of strategic models for regional areas using household travel surveys conducted in metropolitan areas.
Project background
Travel demand models (TDM) are quantitative tools that are used by local, regional, and national planning organisations for the development of evidence-based transport policy. TDMs can offer insights on current patterns of travel behaviour and provide a framework for predicting changes in behaviour in response to changes in the transport system.
Forecasts from TDMs are used to determine the capacity that new infrastructure must provide; and to facilitate the economic, environmental, and social impact assessments of competing initiatives.
The South Australian Department for Infrastructure & Transport (DIT) is responsible for the delivery of effective planning policy, efficient transport, and valuable social and economic infrastructure in South Australia.
The performance of TDMs currently being used by DIT has been undermined by limited resources. In particular, Adelaide last conducted a household travel survey in 1999. That data is now more than twenty years old, and not reflective of current or future travel patterns within the region. There is an urgent need to recalibrate and validate existing models to current data.
As a part of previous work, DIT and UniSA developed and tested an efficient and cost-effective methodology for the recalibration of the Strategic Adelaide Model (SAM) – DIT’s strategic TDM for the Greater Adelaide (GA) metropolitan area – that does not rely on expensive primary data collection methods. In particular, we employed a model averaging approach where we averaged parameters from four different jurisdictions, whilst controlling for outliers, to identify the appropriate parameters for GA.
The present project will build on this previous work to develop a data averaging approach. HTS datasets from different jurisdictions will be combined and reweighted to create a ‘pseudo-HTS’ dataset that is representative of GA, in terms of both the demographic characteristics of the local population, and the level-of-service of the local transport system. This pseudo-HTS could then be used directly to estimate appropriate model parameters for GA. Further, we will examine if and how the methodology could be applied for the development of strategic models for regional SA.
Project objectives
The objectives of the present study are three-fold, to:
1.Examine how changes in sub-model specification could improve the performance of the Strategic Adelaide Model (SAM);
2.Explore how findings from HTS datasets collected in other jurisdictions across Australia could be used to increase the credibility and robustness of SAM; and
3.Develop a data averaging procedure that allows our methodology to be extrapolated to contexts that might differ significantly from where the primary data was collected.
Please note …
This page will be a living record of this project. As it matures, hits milestones, etc., we’ll continue to add information, links, images, interviews and more. Watch this space!
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