Factors affecting public transport patronage growth, 2002-07, Melbourne (DoT)

According to a recent paper, research by the Victorian Department of Transport (DoT) suggests concern for the environment and a healthy lifestyle is a key driver of the recent surge in public transport patronage in Melbourne.

DoT initially concluded that the primary drivers of growth over the period 2002-07 were population growth, higher petrol prices and growth in CBD jobs (see exhibit). Neither traffic congestion nor public transport service quality appeared to play a significant role.

However a large proportion of the patronage increase on trains – equivalent to about 40,000 extra daily passengers – was not explained by the variables and/or the elasticities that DoT assumed in its modelling. This unexplained increase is labelled “Other factors” on the exhibit.

Some research undertaken by Dot and Metlink suggested it might possibly relate to attitudinal factors. Of the top eight reasons given by respondents for reducing their vehicle use, environmental concerns and health & fitness ranked equal second behind petrol prices, but ahead of parking costs.

DoT subsequently undertook a telephone survey of 1500 Melburnians aged over 16 years, asking them about their attitudes to travel options and their existing travel patterns. Using cluster analysis, the researchers identified six main “attitudinal segments”:

Public transport lifestylers (19%) – “Using public transport as much as possible is just the right thing to do. Apart from being a part of my basic day to day life, it has the advantage of being better for the environment when compared to other transport modes”

Public transport works for me (17%) – “I value the time I spend on public transport. I get things out of using public transport that I wouldn’t with other modes”

Public transport rejecters (18%) – “I wouldn’t use public transport even if it was free”

Car works for me (16%) – “Car is the most convenient and useful way for me to get around. It’s not that I have a big problem with public transport; it’s just that it doesn’t suit me as much”

Agnostics (15%) – “I’m just not all that interested in the matter of how I get around. Some people are car people and some like public transport, but I’m not overly fussed either way. If you changed the public transport system, I probably wouldn’t even notice”

Convertibles (15%) – “I use my car mainly but am actually pretty open to using public transport more….but it will need to improve before I do”

Thus according to this research, nearly a fifth of Melburnians are now Public transport lifestylers who “align themselves with public transport due to a strong belief in environmental and sustainability issues, as well as a desire to live a healthy lifestyle”. What’s surprising is that all six segments have almost no (significant) relationship with age, gender, income, education or distance from the CBD e.g. the large Lifestylers segment is not just made up of inner city Greens voters.

While respondents in this segment don’t necessarily all use public transport, the paper concludes that “the results strongly point to attitudinal change having played a significant role in recent patronage growth”.

I’d like to, but I don’t buy the implication that this attitude is a major independent driver of patronage growth. My interpretation is that there’s a cluster of people who have green attitudes and not surprisingly also have a positive attitude to public transport. But I don’t think they’d use public transport in significantly greater numbers if it took longer or was more expensive than the alternatives. They’d use public transport for the same reasons most people do – because for some trips it’s cheaper and/or faster than the alternatives.

I know there’s been growing demand for solar PV cells and water tanks which might be taken as corroborating evidence of a purely green motivation. But buyers of these are still a very small proportion of the population (nothing like 19 %!) and in any event it’s not an ‘apples v apples’ comparison. PV solar is heavily subsidised and financially attractive – feed-in tariffs have been very generous. Water tanks provide a tangible benefit – access to water to save a valuable garden in the event of severe water restrictions. These are seemingly rational responses made on the information available at the time.

What we’re seeing with the Lifestylers, I think, is a simple correlation between positive environmental/lifestyle views on the one hand and a positive view of public transport on the other. It’s not telling us anything about causation. If nearly a fifth of Melburnians really were motivated to use public transport primarily for ethical reasons, I’d also expect to see big changes in air travel, given it has a very large negative environmental impact – a lot more people holidaying in, say, Leeton rather than London, or Portsea rather than Paris (or Port Douglas). I’d also expect to see cycling account for more than 1% of trips. And I’d wonder why the attitudinal effect only applies to trains and not trams.

I don’t know what really does account for the unexplained part of rail travel shown in the exhibit, but I’d be looking first at the elasticity assumptions underlying the variables used in the model. I’d look very closely at why traffic congestion shows up as having such a small effect and I’d want to know if the population growth assumptions adequately account for the mode preferences of overseas students. Most of all I’d look closely at the survey methodology including the level of confidence I’d have in the telephone survey.

I don’t mean to disparage DoT’s research effort – which seems quite sophisticated – I just disagree with the interpretation in this particular case. I do think however that DoT needs to give adequate resources to research, as it underpins billions of dollars in capital investment and operating benefits (or disbenefits!). Rather than spending a few million on research projects, the department should be thinking in terms of whatever’s necessary to get it right up front.

(As an aside, I don’t think “improving health & fitness” is an attitude — in my book it’s a tangible benefit, just like, for example, cheaper fares).