What Happens When Government Workers Move to the Suburbs? The Transport Impacts of Planned Employment Decentralization in Brisbane

Abstract

What are the transport effects of government office decentralization policies in cities with strong mono-centric structures? Decentralization may be defined as the process by which city-regions increase the proportion of jobs that are located outside of their central business district (CBD) and its immediate frame. There is a resurgence of state-led decentralization activity in Australia, with governments promising to move 20% of all city center public servants out to middle- and outer-suburban locations in two of the largest cities, Perth and Brisbane, within a decade. Yet the transport impacts of these policies have not been assessed or meaningfully considered by government. Two key research activities are reported on to address this research gap. An extensive review of previous modeling and travel behavior studies on mono- vs. poly-centric urban structures and of workplace relocation programs is summarized. This highlights mixed results for the transport sector, and identifies possible research paths to identify impacts for cities where decentralization is proposed. This leads to a large modeling effort using the multi-modal Brisbane Strategic Transport Model, examining the likely impacts under specific decentralization scenarios for Greater Brisbane. Results are provided in terms of modal shares, vehicle kilometers travelled, travel time, levels of service on key links and transit patronage. The type of decentralization policy selected has effects on reverse commuting and transit use. The results suggest only those policies directing employment to key rail and busway nodes will mitigate potentially adverse impacts.