Public Transport

Over the last two decades, public transport usage has grown tremendously in Melbourne. By way of example, in the two years from Dec’06 to Dec’08, usage across train, tram and bus increased by 21%. Patronage growth on metropolitan trains was in fact even stronger, growing by 39% in the three years from Apr’05 to July’08, averaging double digit annual growth.

At the time, there were are thought to be a number of factors driving these changes, such as strong population growth, strong employment growth (particularly in the CBD) rising petrol prices (93c/L in Jan’05 compared to $1.61/L in Jun’08), increases in the proportion of the population that is in some way environmentally concerned, and similarly, increases in the proportion of the population that is oriented toward health and wellbeing, which can also have bearing on transport mode choice.

At the time we were briefed by the client, the Victorian Department of Transport, these factors had conspired to reduce the accuracy of the forecasting models used to predict public transport demand.

The Brief

Nature was commissioned to disentangle the relative importance of these factors in driving shifting patterns of consumer transport mode choice.

The Approach

The study used a three-stage approach:

Stage 1 was exploratory in nature, involving in-depth interviews, to uncover the full range of factors at play in influencing commuters’ choice of transport mode, so as to ensure exhaustiveness of Stage 2.
Stage 2 involved derivation and examination of a segmentation (based on telephone interviews) which comprised 6 groups varying in terms of their basic orientation toward public transport versus private vehicle use for the trip from home to work.
Stage 3 involved an advanced choice modelling approach in which interviews were customised to each individual respondent’s own situation. As such, only those modes of transport that were available to respondents were shown to them, to ensure a high degree of realism in the choice modelling task and the elicitation of high quality data for purposes of econometric modelling

The Result

In a nutshell, our research has provided two key sets of insights to the client. The first has been to provide empirical evidence on and clarity around the reasons underpinning what have been largely unpredictable recent historical shifts in public transport patronage. The second has been to provide input as how public transport future demand models should be fine-tuned to take into account hitherto discounted influencers.

A full paper for this study is in the public domain and can be obtained by contacting Nature.