So we're still having a debate about light rail in Canberra that seems to have two poles to it. Pole 1 could be said to be the "cost-benefit position". The argument here is against light rail because it delivers its core benefit of transporting users at too high a cost, relative to buses.
Pole 2 could be called the "transformation position". This side argues that LRT is much better than buses at delivering a whole heap of non-transportation benefits, especially economic and land development, because of its permanent infrastructure and better user experience. But as anyone who lives on the planet Earth knows, there is a whole lot between two poles.
Almost no one disputes that there needs to be a significant "modal shift" of travellers in Canberra from cars to transit and active travel such as cycling and walking. This shift is a stated goal of ACT government policy and for good reason: excessive dependence upon cars has significant external cost in terms of emissions and public health costs such as obesity, and any traffic modeller can tell you it does not take much growth in car trips in a fixed road network to create exponential increases in the occurrence of traffic jams.
This is basic hydraulics, too much fluid in a pipe of a set circumference so to speak, and Canberra is definitely at a critical point there. It won't take too much more population and economic growth to create regular and serious congestion incidents.
However, the real issue comes down to how we effect this shift. Non-transport benefits such as economic growth and urban transformation will flow from the nature and effectiveness of the transport solution and for a simple reason: this is a transport investment, not, say, a water or electricity or residential project. It has to deliver transportation benefits first. If it doesn't do that, it will be a failure from the get-go. If it does deliver benefits but at a very high cost then it may not be a failure, but there may be more effective solution available and we should explore what those are.
The current debate, however, hangs up on the transport mode dimension of a multidimensional problem. Both poles of the debate fall into this trap. The cost-benefit position says LRT delivers trips at too high a cost but ignores most everything else. The transformation position says that buses don't deliver urban development benefits adequately but largely sidesteps the important cost of user transport delivered by LRT.
The desired policy outcome, however, is really important. I would argue that the first desired outcome of any transit system improvement is increased user accessibility and mobility via non-car modes. Accessibility refers to the giving travellers the widest possible portfolio of feasible choices of getting to and from desired origins and destinations.
To oversimplify this comes down to the breadth and width of the transit network on offer. Mobility refers to the ability to actually execute those choices, getting to and from places in the preferred time frame and trip time. Oversimplified, this boils down to transit schedule, frequency and time length.
If all this is achieved then one can start to consider the flow-on effects from improved mobility and accessibility, including economic development and urban place and space design, with, of course, feedback between the two in the actual project and program design and plan.
Mode choice is not neutral with respect to either of these aspects. But to start with a debate about mode choice is, in my opinion, to put the horse before the cart, if we want to invoke an older form of transport.
Understandably, users generally prefer rail over buses when given that choice alone. But urban and transport planners must take a system view and do a trade-off analysis to arrive at the best system outcome that delivers effective and efficient transit mobility, accessibility and wider economic, social and health benefits.
Bus systems such as Bus Rapid Transit are cheaper to build and operate and for a given dollar, properly spent, deliver more transport benefit in terms of accessibility and mobility than LRT. LRT, on the other hand, has advantages in terms of what is referred to as Transit Oriented Development, especially densification around stations which is a key driver of wider economic benefits.
But modes do not operate in a vacuum. To say that rail is better than bus, for example, is like saying scissors are better than knives. It depends upon the task at hand and the desired result and the two are not mutually exclusive. The debate over light rail is deeply unsatisfying because the basic goals we are trying to achieve have been largely lost in a fracas over modes. We should stop confusing means with ends.
Cameron Gordon is associate professor of economics at the University of Canberra's faculty of business and government, and an adjunct associate professor with the Health Research Institute at UC.