Modal image: candidate drivers of preference differences for Bus Rapid Transit and Light Rail Transit

David A. Hensher - Institute of Transport and Logistics Studies, The University of Sydney Business School, University of Sydney, Sydney, NSW , Australia

Corinne Mulley - University of Sydney Business School, University of Sydney

Published online: 18 March 2014

Abstract

The physical image of transport systems, as perceived by users and non users, has long been put forward as a powerful influence on the formation of preferences. One setting for this is in the choice between bus rapid transit (BRT) and light rail transit (LRT) where there appears to be a strong preference in favour of LRT in developed countries and the reverse in developing countries. Using data collected in six capital cities in Australia in 2013, in which individuals rated two BRT and two LRT designs presented as physical images, we develop a full rank mixed logit model to identify candidate sources of influence on image preferences. These provide signals to assist in preparing the ground for a segmented profile for policy makers and politicians to understand how to underpin building a rational debate for modal options in our cities.

Discussion and conclusions

This paper has used specially designed pictures of public transport modes, against a common background, to investigate the role of physical image in defining preferences for public transport. This has allowed the concept of image to be examined without deconstruction into a set of attributes for respondents to consider. This focus is especially pertinent when establishing the perceptions of specific modes that appear to be a driver of potential prejudices towards or away from a given modal technology.

Using a mixed logit model to identify the preferences for the full rank of four modal images, the findings suggest considerable support for many of the ideas identified in the literature. It would appear that ‘bus’ has a relatively bad image, and that BRT suffers from its indirect association with bus,5 with a very high preference for non-bus images. This also supports the broader literature (e.g., Merrilees et al. 2009) on the symbolic and affective impact of images on respondent’s choices.

Surprisingly, we found that there is no strong evidence to support the view where BRT is more widespread than LRT (as in Brisbane and Adelaide), independent of real experience in using the available modes, that this is likely to be a strong factor supporting BRT.  BRT’s negative image, due to the proximity of ‘Bus’ and BRT, can in part be explained by the representativeness heuristic of Tversky and Kahneman (1974). It is also in line with the results of Barlach et al. (2007) who found a negative image of bus relative to rail in an intercity corridor in Israel, despite similar travel times; and also Innocenti et al. (2013) who found a strong car image causing myopic mode choices in the laboratory, even when an LRT alternative had a better level of service and when respondents receive immediate feedback on the results of their choices through experience.

A key finding of our study, however, is that the image effect is mediated by previous usage experience of specific modes. If a positive experience is attributed a priori to an alternative, the evidence suggests that the image is less dominant in preference revelation (implying that the service levels are a defining influence). The proximity to experience with close modes, as in LRT and train (and bus and BRT) is also an important finding. The challenge, where there is evidence of the role of a positive (i.e., real) experience (for bus and BRT) as a mediating factor on image, is to pick this message up and reinforce it.

Income, a variable not given much attention in the image literature, also plays a role.  Increases in personal income are associated with an increasing preference, relative to BRT (standard and modern), for the LRT modern and standard images even though in the latter case there is a decreasing preference for the light rail standard image.

Apart from investigating the role of image in forming preferences, the results of this investigation offers understanding to policymakers (and politicians) of the role of image in the community’s view of different modal options. Specifically, this research shows that it is important to take account of image in the promotion of different modal options and that information to inform might be best undertaken by segmenting the market by experience, income, and age as well as the physical attributes of the vehicles. In general, the role of experience and learning on travel choices has been long identified as an ongoing gap in the transportation literature, including in particular the travel demand modelling field. The results reinforce the existence of this gap and show the necessity for more research.

 

 

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