British study questions LRT's ability to change commute habits

From the SurreySide blog, managed by Patrick Johnston, who writes occasional posts looking at development, city planning and transportation.

Trains for Surrey: Light rail is far from the perfect solution to reducing congestion – Cardiff University study

An interesting report over at The Atlantic Cities on a UK study about the impact of light rail on commuter mode-choice.

The study by researchers at Cardiff University  has found that simply building light rail doesn’t seem to reduce car usage:

Growing rail shares in the light rail corridors have mainly come from buses and the evidence for light rail reducing car use is less clear. This latter finding is of particular significance, given that a major justification for investment in light rail rather than bus schemes is their presumed ability to bring about major modal shift by attracting substantial numbers of car users.

The researchers found that what light rail does do is reduce usage loads on buses:

A similar new study of British light rail systems comes away far less hopeful. In an upcoming issue of the Journal of Transport Geography, planners Shin Lee and Martyn Senior of Cardiff University found that the evidence for light rail reducing car use is unclear. Lee and Senior discovered that car ownership and car commute share often continue to rise in these corridors, and that ridership growth is often the result of travelers shifting over from buses — not cars.

For their study, Lee and Senior look at four light rail systems completed from 1991 to 2001: the Manchester Metrolink (built in two phases), the South Yorkshire Supertram, and Midland Metro, and the Croydon Tramlink. To determine the impact these lines had on their respective corridors, the researchers located nearby “control” areas to represent travel behavior that might have occurred if the systems hadn’t been built. The control and light rail areas had similar car ownership levels before 1991, similar rail commuter shares, and a similar distance to nearby city centers.

The Atlantic’s Eric Jaffe does not some concern about aspects of the study but also finds an important lesson:

The work makes a good contribution to our understanding of urban transit, but it has some severe caveats. The study’s biggest limitation is that it focused on the simple existence of light rail — not the quality of its service, or for that matter other factors like density or development or demographics. In the case of the Midland corridor, for instance, all of the findings are compromised by the fact that a major road was built parallel to the light rail line; a city that creates an incentive to drive shouldn’t be surprised when people do.

With that in mind, the work still underscores some important lessons. For starters, it offers a sound piece of advice: cities considering a light rail system should strongly consider whether improving the local bus system would be cheaper and just as effective. It also provides yet another reminder of the irrational love people have for their cars; getting city residents to give up driving often requires more than just offering them a ride.

Anyone who has observed commuters in the Lower Mainland can cite plenty of people who still drive despite having a viable transit alternative.

Surrey’s transportation planners should keep this in mind.