The Department for Infrastructure and Transport in South Australia developed the Tactical Adelaide Model (known as TAM) to provide a brand-new industry paradigm via a maintained and governed multi-modal transportation operational assessment model.

Overview

Transport modelling is a crucial factor in supporting urban design and investment decisions, examining the impact of different land use planning decisions and managing traffic control systems.

While project-specific models are valuable tools, they are frequently developed in isolation from one another and end up differing greatly in shape, size, platform, and configuration. Attempts to create large-scale models by stitching together these project models result in patchwork solutions that are not fit for purpose for wider-scale evaluations and policy making.

The Department for Infrastructure and Transport (DIT) in South Australia wanted to solve these issues by developing a single, unified, consistent large-scale modelling framework; the result is the Tactical Adelaide Model (TAM), led by Transport Analytics in partnership with Aimsun.

The Use Cases

Delivered in May 2022, TAM is the heart of DIT’s modelling framework and has already proven invaluable in supporting network planning decisions. The TAM modelling framework covers the five most critical use cases:

1. Operations – operational changes in the network. Operational analysis is daily, weekly, monthly or seasonal with one-day to six-month horizons.
2. Operational Planning – planned events and operational updates in the network, from three months to five years in the future. This includes significant event planning, major infrastructure construction, infrastructure maintenance planning and public transport operations.
3. Tactical Planning – small and medium operational upgrades and infrastructure upgrades over the next two to six years. This includes road infrastructure upgrades and public transport operations/planning
4. Development Planning – medium and large land-use changes, demographics and infrastructure.
5. Strategic Planning – any strategic infrastructure that impacts land-use planning, city-wide routing, or traffic patterns to assess impacts in a realistic, operationally constrained real-world environment.
   
   

Different Levels of Detail

The default operation of the whole-city modelling framework is at the mesoscopic level of detail, which is dynamic in nature but at a mid-level of granularity to keep computational effort as low as possible and prioritize speed and agility. However, in cases where simulation-based responses might need more detail, such as say, a heavily congested roundabout or junction, Aimsun Next is able provide pockets of microscopic level simulation, zooming into the behaviour of individual road users. These microscopic pockets of simulation would only be considered for special project-based applications or as further enhancements and could be maintained on an on or off basis due to Aimsun’s highly flexible, hybrid model structure.

DIT’s innovative formation of a partnership led by an agile delivery framework and working to a set of overarching principles was an industry first. This approach has proved to be instrumental in delivering the accuracy and robustness of TAM. The solution’s scope has already delivered operational-level project results at a fraction of the time and resources used previously.