Investigating the transit-orientation of existing urban development around Melbourne trams compared to other public transport modes

The travel demands of Melbourne’s rapidly growing population cannot continue to be effectively supported by existing transport infrastructure. Transit-oriented development (TOD) is a planning strategy gaining local traction as a means of meeting the increasing demand for transport sustainably. Much literature relates TOD to rail and light rail but less so to bus. An investigation comparing how transit-oriented the existing urban form is around different modes would be a useful baseline to inform and support planning strategies which favour certain modes on the basis of their potential to achieve planning objectives. This study investigates the extent to which urban development around Melbourne’s transit is intrinsically ‘transit-oriented’, by measuring indicators of TOD for catchment land use of trams, trains and buses, including SmartBus and local bus routes, for a representative sample through inner, middle and outer Melbourne. The hypotheses tested were that the extent of transit-orientation varies with mode, and that tram is associated with sustainable patterns of urban development that is significantly higher quality than other modes, notably bus. Mapping software was used to develop a census profile for each circular catchment. A multi-criteria index, the TOD score, was developed to quantify the transit-orientation of the built environment in terms of walkability (design), land use entropy (diversity) and population density. TOD score was regressed on explanatory variables and the artificial variable of mode, to test the above hypotheses. Results showed that the TOD Score of tram catchments was higher than that of bus and rail, suggesting that the development around tram nodes is more transit-oriented. However, once proximity to the central business district was incorporated into the analysis, no significant variation was apparent between modes, with the exception of SmartBus, which showed no significant effect on TOD score compared to areas of low transit provision. This result suggests that the close proximity of tram catchments to the CBD is responsible for the high TOD scores achieved. The results identify areas for future research into the potential for bus TOD and the progression of tram TOD strategies.