Traffic Impact Assessments

Triggers of Traffic Impact Assessments

Road authorities (VicRoads, local councils or other state authorities depending on location) will request a Traffic Impact Assessment (TIA) for most Planning Permit applications where the development is expected to generate traffic volumes likely to alter the existing operations of the surrounding network, or impact surrounding parking facilities, access points, intersections or pedestrian and cyclist movements. As the Council's Statutory Planner reviews the planning submission alongside the town planning drawings, they assess whether the application requires a Traffic Impact Assessment.

If you are handling your Planning Permit Application through an architect, town planner or building designer, they may receive a Request for Information (RFI) upon lodging your application asking for a Traffic Impact Assessment, or a Car Parking Demand Assessment for minor developments. TIAs are often requested for developments starting from as few as three townhouses or units through to larger residential, commercial, retail or industrial developments. As a rule of thumb, the larger the development, the higher the chance a TIA will be required.

Contents of a Traffic Impact Assessment

Most projects have some level of impact on the surrounding traffic or parking environment, so it's vital that these impacts are carefully analysed and managed with traffic, parking, access and road safety engineering treatments. A traffic impact assessment provides key design inputs for urban designers, planners and architects, shaping designs to minimise adverse transport impacts while still achieving the best possible outcome. This has the most value when produced early in a project, since being pro-active can save significant redesign costs later.

A RedSquare Traffic engineer preparing a TIA looks at a range of factors including potential impacts on the local community and amenity, network-wide operational impacts (especially at nearby key intersections), road safety issues resulting from the development, alignment with current and future government strategies, impacts on cyclists, pedestrians and public transport, compliance with local planning schemes, and future-proofing for upcoming changes in the road network.

Key Steps in Developing a Traffic Impact Assessment

• Description of existing conditions - a comprehensive desktop review and on-site assessment capturing the key features of the surrounding road network, including nearby roads, car parking facilities and restrictions, intersection operations, traffic volumes, crash history and active/public transport provisions.
• Description of the proposed development - identifying and summarising the key features of the development relevant to traffic, parking and access design.
• Identification of key stakeholders - road users, nearby businesses and road authorities who may be affected by the development.
• Review of applicable Planning Scheme clauses, overlays and Australian Standards relevant to the development's location, size and operations.
• Statutory car parking requirements - a comprehensive car parking assessment against Clause 52.06 of the Planning Scheme (or the relevant state equivalent), including a car park design review against AS2890.1, AS2890.2 and AS2890.6. Where the proposed parking falls short of requirements, a Car Parking Demand Assessment is prepared to justify the shortfall.
• Traffic impact assessment - predicting the vehicle trips generated by the development, where they originate from and which roads they approach, then comparing this against existing conditions to assess whether the difference creates a noteworthy impact. Larger developments may require formal access point design, including turn lanes.
• Swept path analysis - simulating the manoeuvring of vehicles within car parking areas, often produced as a standalone document as well as part of the TIA.
• Review of internal road layout - for larger residential and retail developments with an internal road network, reviewing whether traffic management treatments such as speed calming, footpaths, crossings or roundabouts are required.
• Mitigation measures - a summarised list of recommendations addressing each of the items above, either resolved pre-application, during the RFI stage, or as conditions of the Planning Permit.

A carefully developed Traffic Impact Assessment increases the probability of your Planning Permit Application being approved without much hassle, and gives strong justification that the development is suitable for its neighbourhood. RedSquare Traffic's experienced traffic engineers can assist you throughout this process, from start to finish.