Transport Assessment and Modelling

Transport Impact Assessment (TIA)

TIA is a process of compiling and analysing information on the impacts a development or infrastructure proposal may have on roads and transport networks.

The assessment includes general impacts relating to transport management, such as road efficiency and safety. It also considers specific impacts on all road users, including on-road public transport, pedestrians, cyclists and heavy vehicles.

Guidelines

The ACT TIA Guidelines provide practitioners and stakeholders involved in land-use  and transport planning a reference document for managing TIAs resulting from land-use development proposals. The guidelines aim to promote a common understanding of the process aligned with the national transport management guidelines. They can be tailored to the ACT’s statutory requirements, policies and strategies.

While the Austroads Guide to Traffic Management Part 12: Integrated Transport Assessments for Developments provides guidance on how a TIA should be undertaken, the ACT TIA Guidelines focus on what is required. Specifically, they aim to:

• outline the necessary matters to be considered in a TIA and provide a more transparent process
• ensure that sustainable transport goals and strategies are incorporated into the TIA process
• provide development thresholds to indicate when larger development proposals need a TIA.

The 2025 ACT TIA Guidelines Update was recently completed as part of the new planning and development processes and following two industry briefings are now released to the industry for a 12-month trial effective 1^st of July 2025, and are available on the Standards, codes and guidelines page.

The updated ACT TIA Guidelines provide a more robust framework for when and how to assess the traffic and transport (multimodal) impacts of both trip generating proposals and other land use and infrastructure projects which may change or alter the transport network.

Data request and fees

From 1 July 2023 fees were introduced for transport and traffic data related requests. These fees are published on the City Services website.

Please email your request for data to CED.dcdevelopmentcoordination@act.gov.au. We will provide a link to the online application form where payment for the data request can be made. Following receipt of payment, we will notify you via email that your data request has been assigned to a project lead who will commence processing your request.

For information on timeframes for processing data requests, please see General Advisory Note 07 (PDF 331.1 KB).

Links

Austroads Guide to Traffic Management Part 12: Integrated Transport Assessments for Developments

ACT Traffic Microsimulation Modelling Guidelines (PDF 1.3 MB)

Guidelines for SIDRA Analysis (PDF 331.1 KB)

ACT Government ACTmapi

Canberra Strategic Transport Model (CSTM)

The CSTM is the overarching strategic transport model for Canberra providing a strategic overview of the interaction between land use planning and the future transport network. Its primary function is to forecast travel demand for future land use and transport infrastructure scenarios and to provide estimates of traffic growth for operational models.

The CSTM is used by the ACT Government to evaluate future network performance and infrastructure needs. It allows assessment of feasibility of transport network upgrades, and scenario testing of land use and various travel cost parameters such as public transport fares, parking fees and fuel costs.

The CSTM is a  multi-modal transport planning model hosted in TransCAD platform. It simulates where Canberrans are moving to and from based on trip purposes and land use, how Canberrans make the trips using generalised costs and trip propensities (e.g. by car, public transport and/or bicycle), and which routes of the network Canberrans are likely to take.

The model simulates peak traffic based on assumptions including land-use (population, employment, retail space and enrolments), transport network (road, public transport, and bicycle) and transport cost parameters (parking, fuel costs and bus fares).

The basic CSTM outputs include volume-capacity (congestion) plots, plots showing forecast volumes of car traffic, public transport passenger volumes and bicycle volumes in various model years, and origin-destination matrices by trip purposes and mode.

CSTM Enhancements and Recalibration (CSTM2)

The CSTM2 is significantly enhanced as part of the four-year Connected and sustainable Canberra – Modelling transport across Canberra initiative.  CSTM2 is also recently recalibrated based on 2023 conditions including the ABS Census demographic and journey to work data, the updated trip rates from the 2022 Household Travel Survey and traffic conditions. It comprises future base case model scenarios at five yearly intervals from 2026 up to 2051. In addition to ACT districts, it covers the NSW districts of Queanbeyan to the east and Yass Valley to the north.

CSTM Stage 1 enhancements:

• Input data updates ((zone structure and land use, transport networks – roads, public transport, park and ride, active travel, and cost parameters (value of time, parking costs)
• Assignment improvements – volume delay functions, multi-class traffic assignment presenting traffic flows per trip purpose, and capacity constrained PT assignment.

CSTM Stage 2 enhancements:

• Expansion of AM/PM peak time periods into all day with four time periods including AM peak (07:00-09:00), PM peak (15:00-18:00), Inter-peak (09:00-15:00) and Night-time (18:00-07:00)
• More trip purposes including home-based work white collar and home-based work blue collar and home-based education primary secondary and home-based education tertiary.
• Light rail calibration
• Inclusion of walking, freight and visitor trips
• Development of data analysis toolkit and updated dashboard.

In line with the new planning system, the CSTM2 population projections at the territory level is based on the ACT Treasury population projections and distributed at the district level based on the ACT District Strategies.

Household Travel Survey Dashboard

The CSTM has been recalibrated using data from the 2022 ACT Household Travel Survey. The survey collected information on why, how, when and where members of a selected household travel over a single day.

A total of 2,078 households and 5,106 people in the ACT and Queanbeyan contributed to the survey and completed a travel diary for a single specified day.

The survey outcomes help inform transport planning and policy development for the ACT and Queanbeyan area.

The ACT and Queanbeyan Household Travel Survey data dashboard was recently updated to include a comparative analysis of the 2017 and 2022 survey outcomes and is available on the Transport Canberra website and the ACT open data portal to support additional analysis and sharing outcomes with relevant entities.

Data request and fees

From 1 July 2023 fees were introduced for transport and traffic data related requests. These fees are published on the City Services website.

Please email your request for data to CED.dcdevelopmentcoordination@act.gov.au. We will provide a link to the online application form where payment for the data request can be made. Following receipt of payment, we will notify you via email that your data request has been assigned to a project lead who will commence processing your request.

For information on timeframes for processing data requests, please see General Advisory Note 07 (PDF 331.1 KB).

Links

2017 ACT and Queanbeyan-Palerang Household Travel Survey

2022 ACT and Queanbeyan-Palerang Household Travel Survey

ACT Government Open Data Portal

Mesoscopic/Microscopic traffic models

While strategic transport models inform forecast travel demand for the whole transport system, operational traffic models consider detailed vehicular movement and their impacts on the road network operation. These includes mesoscopic, microscopic and intersection models.

Operational models use travel demand forecast data from the Canberra Strategic Transport Model (CSTM). They simulate the movement of individual vehicles through the road transport network either by public transport (light rail and/or buses) or cars.

They include information on:

• the road transport network
• traffic controls (including intersection controls, parking, traffic signal, control timing and coordination)
• the number of vehicle trips Canberrans make by motorised modes in peak periods.

City and Inner North Reference Model (CINRM)

The CINRM is a hybrid mesoscopic and microscopic model. Its primary function is to simulate detailed traffic impacts at a local level. This helps to inform infrastructure planning including development approvals, engineering design and community consultation.

CINRM is a detailed digital representation of the road transport network of the City and Inner North. It is based on the earlier City to Woden (C2W) model developed for the Canberra Light Rail Project with updated zoning boundaries aligned with CSTM.

The CINRM comprises base case scenarios for 2019 and future year reference scenarios for 2026 and 2031. The 2026 and 2031 models were recently updated based on latest Canberra Strategic Transport Model (CSTM2) origin-destination traffic demand matrices. The main CINRM outputs include traffic flow, traffic delay, level of service and travel times within the City and Inner North for each reference model.

Woden Valley Reference Traffic Model (WVRTM)

The WVRTM comprises base year 2021 and future year 2026 and 2031 reference models for morning and afternoon peak hour traffic periods. The WVRTM aims to support a place-based approach and assessment of the ACT Government’s delivery sequencing of transport infrastructure in the wider Woden Valley precinct.

These reference models include the future traffic growth and committed infrastructure projects such as the Light Rail Stage 2B between Commonwealth Avenue and Woden Town Centre.

The WVRTM has expanded to include:

• the Athllon Drive Duplication project
• the Light Rail extension to Mawson
• the proposed Athllon Drive high density development of 645 dwellings outlined in the 2024-25 Land Release Program.

The expansion of the study area further south was to capture the travel route choice patterns to and from the far southern suburbs such as Tuggeranong, Gowrie and Wanniassa.

Gungahlin Reference Traffic Model (GRTM)

The GRTM comprises a base year model calibrated to 2022 conditions and future base year models for 2026 and 2031. The GRTM aims to provide the ACT Government with accurate and simulation-based road and intersection performance outputs as forecast traffic volumes, travel times, queue lengths and congestion delays.

The GRTM will assist assessment of land use and transport impacts. It will inform evidence-based infrastructure planning and prioritisation of road network upgrades. This includes intersection signal configuration improvements required to accommodate development intentions in Gungahlin.

Bruce Precinct Traffic Model (BPTM)

The BPTM comprises a base year model calibrated to 2024 conditions and future base year models for 2031 and 2041.

The BPTM aims to assist in identifying the infrastructure needs to support the anticipated redevelopment intentions within the Bruce Precinct primarily the North Canberra Hospital (NCH) redevelopment project and other future redevelopments. These could include key intersection configurations and access/egress locations for all road users to and from the development.

In addition to the base models, BPTM also includes project model scenarios for 2031 and 2041 to assess the traffic impacts including the NCH redevelopment land use and network assumptions.

Guidelines

The ACT Traffic Microsimulation Modelling Guidelines (PDF 1.3 MB) provide guidelines on model development, calibration and validation, and documentation of results. They also provide guidance on input parameters, calibration, and validation criteria, expected outputs, and the required reporting structure.

The guidelines aim to facilitate an easier and more systematic process to assess microsimulation model quality and model outputs. This helps to ensure that traffic models and reports produced by different people or organisations will achieve a certain level of consistency that is acceptable to the Directorate.

Data request and fees

From 1 July 2023 fees were introduced for transport and traffic data related requests. These fees are published on the City Services website.

Please email your request for data to CED.dcdevelopmentcoordination@act.gov.au. We will provide a link to the online application form where payment for the data request can be made. Following receipt of payment, we will notify you via email that your data request has been assigned to a project lead who will commence processing your request.

For information on timeframes for processing data requests, please see General Advisory Note 07 (PDF 331.1 KB).

Data and SCATS (Sydney Coordinated Adaptive Traffic System)

Data Provision

As part of the transport impact assessment process, the Directorate supports development proponents by providing:

• transport data from actual surveys and the Sydney Coordinated Adaptive Traffic System (SCATS)
• Canberra Strategic Transport Model (CSTM) outputs
• SCATS traffic signals operation and
• mesoscopic/microscopic reference traffic models (CINRM, WVRTM, GRTM and BPTM).

Both CSTM and mesoscopic reference traffic model outputs include congestion plots and traffic volumes and associated link characteristics (number of lanes, speed, capacity). They also both include underpinning land use data (population, employment, retail space and enrolments) and future road network improvements assumptions. Whereas, the SCATS data includes traffic volumes, traffic signals phasing operation and associated intersection parameters.

The proponent may need to undertake further transport and traffic modelling. This could include microsimulation and intersection modelling to meet the desired requirements to support the proposed development in the project scenario.

Please note that if the traffic study is related to the ACT Government project, the data will be provided free of charge. For non-ACT Government project related studies, data requests will be charged as per the fee rates outlined on the City Services website.

If the proposal is not for a project on behalf of the ACT Government, please direct your request for SCATS data to Roads ACT via Access Canberra 13 22 81 or trafficsignals@act.gov.au.

Data request and fees

From 1 July 2023 fees were introduced for transport and traffic data related requests. These fees are published on the City Services website.

Please email your request for data to CED.dcdevelopmentcoordination@act.gov.au. We will provide a link to the online application form where payment for the data request can be made. Following receipt of payment, we will notify you via email that your data request has been assigned to a project lead who will commence processing your request.

For information on timeframes for processing data requests, please see General Advisory Note 07 (PDF 331.1 KB).