A best practice evaluation of traffic impact assessment guidelines in Australia and New Zealand

Traffic impact assessments (TIAs) are crucial to understanding how a proposed development will impact the surrounding transport network. Various national and state TIA guidelines are available throughout Australia and New Zealand, but there is little understanding of the extent to which these guidelines constitute best practice in TIA. This research aims to understand what a standard of best practice means in the context of TIA and to what extent the Australian and New Zealand TIA guidelines represent this standard.The research included an evaluation of the national guidelines for Australia and New Zealand, as well as state/region specific guidelines from New South Wales, Queensland, Tasmania, Western Australia and Auckland. An international literature review of best practice in TIA was undertaken to inform the development of an assessment framework using on a ‘scorecard’ approach. This scorecard was then applied to assign numerical weight to reflect the extent to which each TIA guideline met best practice standards.The evaluation found that the state guidelines from Western Australia and the Australian national guidelines scored highest, achieving 55% of the maximum possible score. The guidelines from Queensland and New South Wales scored marginally lower with 45% and 48% of the maximum possible score. This was followed by Tasmania (30%), Auckland (29%) and the national guidelines for New Zealand (23%). The results highlighted a number of key areas for improvement, particularly those related to legislative frameworks, multi-modal transport considerations, and the monitoring and review of TIAs. The conclusions of this research are indicative only, and limited to the breadth of literature review that informed the paper. Further research should seek the opinions of academics, various transport stakeholders and industry participants to revise and refine the framework in order to provide a more accurate standard with which to measure best practice.