How can transport impacts of urban growth be modelled? An approach to consider spatial and temporal scales

The urban transport sector is responsible for a considerable portion of the global greenhouse gas emissions, and considered as a primary contributor of environmental pollutants. This study aims to explore ways to compare transport impacts of alternative urban growth scenarios at different spatial and temporal scales. To achieve this aim, alternative policy scenarios and various transport impact indicators were synthesized from a Delphi survey. Four alternative urban growth scenarios (i.e., business-as-usual, environment-focused, economy-focused, balanced scenarios) for the South East Queensland Region of Australia were evaluated by comparing selected indicator values from transportation models developed for three spatial (i.e., region, city, local) and four temporal (i.e., 2016, 2021, 2031, 2041) scales. The results of the analysis disclose that policies under the balanced scenario make the highest contribution towards achieving sustainable urban development-as this scenario generates the least travel time, travel distance, and traffic congestion. The findings reveal that the empirical approach put forward in this paper is useful to inform urban policymaking, and assist urban policymakers, urban/transport planners, practitioners, and stakeholders.