Myth: Heavy rail costs too much; we should build light rail instead

Myth: Heavy rail costs too much; we should build light rail instead
Fact: It all depends on the magnitude of the task. The PTUA advocates extensions to the heavy rail network to serve large areas with no existing rail service. Given the populations of these areas, heavy and light rail cost about the same once you buy enough vehicles to carry the required number of passengers.

Since the 1980s, many of Melbourne’s public transport bureaucrats and managers have become fixated with ‘light rail’ (a high-falutin word for ‘tram’) as a replacement for traditional ‘heavy’ rail systems. Light-rail enthusiasts scored an early victory in 1988 when the St Kilda and Port Melbourne train lines were closed and converted to tramways, with the result that a quarter of a century later, people are being sardined onto overcrowded trams, or being left behind altogether.

The experience with the St Kilda line is an object lesson in how substituting a tram line for a train line cripples its capacity. While a tram service can run at around three times the frequency of a train service (largely by running at lower speed), a train can carry ten times as many passengers as a single ‘light rail’ vehicle. This means firstly, that the overall capacity of a light rail line is only around one-third that of a heavy rail line, and secondly, that cost savings in building a light rail line instead of a heavy rail line are largely cancelled out by the need to buy more vehicles (and hire more drivers) to carry the same number of passengers. So while trams are ideal for providing service in a single narrow corridor, public transport service on the whole-suburb scale requires a heavy rail backbone.

Thus, when Professor Bill Russell did the first major feasibility study for a rail line to East Doncaster in 1990, the costings for heavy rail and light rail came out almost equal: $250 million for heavy rail versus $242 million for light rail. Costings have since gone up with inflation, but nothing has happened that would alter the relative figures. Given this, one would think that to get the most bang-per-buck, the government would insist on heavy rail rather than light rail for a future Doncaster line. Yet the Northern Central City Corridor Study released in 2003 not only said nothing about the heavy rail option, but recommended only a ‘feasibility study’ into a light rail line to Doncaster! Only since 2010 has the community succeeded in having the government consider a heavy rail line at all.

Like Doncaster, Rowville is a well-established postwar suburb with no rail services whatsoever. A rail extension along the Wellington Road alignment from Huntingdale to Rowville would provide a much-needed high-capacity backbone to support expanded bus services throughout the Rowville, Scoresby, Mulgrave and Endeavour Hills region. It would also provide a vital service to Monash University, one of the largest single trip generators in the south-eastern suburbs with a commuter population exceeding 20,000. Yet again, prior to 2010 all the bureaucrats were prepared to propose was a possible network option of a tram line from Huntingdale to Monash University. This would likely have cost more than a train line with the same capacity, due to the need to establish depot and other facilities remote from the existing tram network.

Enthusiasm for light rail doesn’t end with proposed new lines: even before the Rowville or Doncaster lines were on the agenda, and despite the problems that have resulted on the St Kilda line, government bureaucrats in the 1990s had no shortage of plans to replace existing rail lines with the inferior light rail alternative. The Upfield line was slated for closure in the early 1990s, before the government was convinced to save it and upgrade it instead. And of course the Alamein line, which comes under threat every twenty years or so, is also a popular target of light rail enthusiasts.

How does one explain this counterproductive light rail fetish? In part it may just be the perception of newness: ‘heavy rail’ conjures up an image of clunky 19th-century steam trains, while ‘light rail’ has modern, shiny, up-to-date connotations. One might expect this attitude from naive non-experts, but would expect high-level planners to weigh up the actual evidence for or against alternative technologies rather than just follow fashion. The less charitable explanation is that our planners do not want a high-capacity system, because they secretly believe public transport is doomed. This would be consistent with their refusal to consider new suburban rail extensions (despite pouring generous funds into roads year after year) and with their overall defeatist attitude toward attracting new public transport patrons.

Melbourne is fortunate to have inherited one of the largest train networks for a city of its size anywhere in the world. To complete this network requires only a few extensions, costing less than a modest urban freeway. ‘Light rail’ is unlikely to save much money and would cripple the potential of new lines to move large populations in the areas they serve.

Last modified: 10 August 2012

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