Merging static & dynamic transport modelling in SE Queensland

Transport network modelling is frequently highly complex. The most appropriate transport modelling applications, however, frequently have as a top delivery priority a true recognition and realisation of the real-world problems for which they are being implemented to inform.

The Queensland Government recognises an urgent need to collaborate growth and planning initiatives alongside with transportation network development, as a priority within the South-East Queensland (SEQ) region. This is particularly the case with the Brisbane 2032 Olympic and Paralympic Games being hosted across SEQ, which has as its target of course not only the games itself, but also a lasting and enduring legacy.

Under this iMOVE initiative, a multi-hub / multi-city tactical, yet still operationally detailed, transportation model is to be developed covering across the whole of South-East Queensland. The model merges previously disconnected static (tactical / strategic / ”macro-scopic”) modelling methods with dynamic (operational reality / ”meso-scopic”) modelling methods, in an approach intended to support development of suitable transportation infrastructure and the associated government policies, under a single SEQ integrated multi-modality mobility plan.

The model is intended to be used as a sandbox in order to test various operational scenarios under forecast demand/growth scenarios, thereby seeking to optimise transportation network operations, whilst suitably protecting inter-urban breaks, such as for example regional biodiversity corridors.

In seeking to do this the project will apply Department of Transport and Main Roads (TMR) expertise in combination with Aimsun software and solutions realm expertise to coordinate and assess the transport challenges of multi-centre regions – Gold Coast, Brisbane, Sunshine Coast, Ipswich, and Logan – via the compilation of an integrated hybrid Regional Macro-Mesoscopic tactical and operations transport modelling ecosystem.

Participants

• • Department of Transport and Main Roads (Queensland)
  • Aimsun

Project background

Transport authorities across the world are responsible for both transport planning and transport operations simultaneously for medium- to longer-term horizons, including for managing networks as efficiently as is possible in their day-to-day operations.

Conventionally, due to technological limitations, plus in order to suitably support network planners and operators in their respective realms, there are limited geographical areas of coverage defined for different types (“tiers”) of transportation network models.

Dynamic modelling tiers have been integrated in an approach led globally by the Aimsun Group through the “Hybrid” Meso-Micro Dynamic Traffic Assignment simulation modelling approach, available across many years in the Aimsun Next software platform.

With recent advancements of technology, and particularly for the processing of large datasets and the simulation of larger area models, Aimsun Next software has leveraged an existing extensive capability in simulation-based prediction for medium- to longer-term transport planning; this particularly in seeking to cross and thereby integrate all transport modelling assignment tiers in as seamless a way as possible.

The integration of a Static Traffic Assignment (Macroscopic) approaches with Dynamic Traffic Assignment (Mesoscopic) approaches offers key potential insights and benefits in terms of spanning across both the tactical planning and operational planning realms via a single integrated modelling platform approach. Of
course such aspects come with a number of technical challenges, and particularly so with respect to the integration of static and dynamic traffic assignment methods.

The following figure illustrates, through the amber polygon, the technical interest area which is focussed here in terms of modelling tiers integration:

By comparison to a more conventional citywide macro or meso model, which adheres to a rigid artificial virtual boundary at the edge of a city, a simulation approach such as a macro-meso hybrid approach, whilst still necessarily needing to define model boundaries, can expand these boundaries more seamlessly across a much wider area. If desirable this can be extended to a whole state or region, covering for multiple major activity centres and cities, whilst retaining sufficient operational details.

The macro-meso hybrid modelling approach thus seeks to ensure that conditions at artificial model boundaries can have minimal impact on overall modelling results, whilst still allowing modellers and planners to assess the impacts of intra- and inter-city trips within a large study area appropriately (such as in SEQ).

Project objectives

The main objectives of this project are to develop a robust SEQ region wide network modelling platform which can be used to support long-term policy and planning, such as during the preparation of South East Queensland Regional Plan (ShapingSEQ), and/or medium-term conceptual infrastructure planning and challenges, such as hosting the Brisbane 2032 Olympic and Paralympic Games.

Thirteen challenges have been identified to date and will be researched and investigated extensively under the project. The primary objectives to be explored are via the model output from the study, covering SEQ via a single Macro-Mesoscopic Hybrid model.

The thirteen identified research challenges are as follows:

1. Ensure consistency with SEQ Strategic Transport Model (SEQSTM) updates.
2. Enable dynamic geographical boundary within the model area.
3. Enable multiple meso models within the wider macro model.
4. Ensure compatibility across the macro-meso boundary.
5. Enable potential temporal extension to other time periods in a day and/or specific days within a year.
6. Ensure compatibility of cost functions across all models to be imported and integrated into the model.
7. Modelling methodology and approach for a multi-centre regional model for an area such as SEQ.
8. Ensure that the model can be used for multi-class assessment.
9. Ensure that the model run can be completed within reasonable time duration.
10. Enable analysis for meso-scopic (dynamic) network as well as macro-scopic (static) network simultaneously, within a single model entity.
11. Enable PT analysis (Traffic operations).
12. Provides SEQ wide traffic analysis tool with standard outputs across both macro and meso network.
13. Identify limitations of such a tool in operation analysis.

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!