Average per capita congestion costs for Australian metropolitan areas (Source: BITRE)

In a new report released this week, the Bureau of Infrastructure, Transport and Regional Economics (BITRE) estimates the ‘avoidable’ average social cost to the community of traffic congestion in Australia’s capital cities is now $16.5 billion per annum.

Most of that social cost ($14 billion) is in the form of time lost by business and private travellers due to delay i.e. sitting in traffic. Only $1 billion is due to extra air pollution.

Greens Senator Janet Rice responded to the release of the report by calling on the Government to increase funding for “congestion busting” public transport.

The world’s major cities that are easy to get around don’t rely on cars. These cities have made a conscious effort to build infrastructure that gives people the option to catch public transport, ride their bike or simply walk to where they’re going.

For decades, our trains, trams and buses have been ignored in favour of great big toll roads with shonky business cases like the East West Link.

We’re not going to reduce these costs to the community by going down the same track of building multi-lane carparks and spaghetti junctions. We must correct this underinvestment and prioritise congestion busting trains, trams and buses, starting with the Melbourne Metro Rail tunnel.

Ms Rice is right that building more roads won’t reduce congestion. BITRE says continuing to provide roads at historical levels will still see an estimated 2% p.a. increase in average delay levels out to 2030.

But her claim that public transport will reduce traffic congestion is wrong (e.g. see Are politicians serious about “fixing” traffic congestion?). She only has to visit a city like Paris to see that even having the best metro in the world hasn’t eliminated traffic congestion.

Or closer to home, go to the CBD of any capital city in peak hour. Public transport and walking account for 80% of commutes to the centre of Sydney, yet the streets are still hopelessly congested in peak periods.

Cars take up a lot of road space. It only takes a relatively small number to generate congestion. And even with top class public transport like the Paris Metro, there’ll always be some travellers who prefer to go by car if the option’s available to them.

The problem is the same one encountered with building freeways; any road space “created” by transferring a motorist to public transport is inevitably taken up eventually by another driver who takes advantage of the spare capacity.

The key benefit of public transport isn’t “decongestion”. Apart from providing mobility for those without the option of driving, its main value lies in enabling the creation of very dense concentrations of activities, typically CBDs.

If there were no mass transit in Australian cities, the city centre would be much less concentrated. Jobs and other activities would be more dispersed, like they tend to be in those car-oriented US cities that developed without rail.

The only way to reduce congestion significantly is to ration access to road space in some way. The obvious one is by charging motorists a price set at the level required to discourage enough drivers (typically around 10%) to keep traffic moving at a reasonable average speed (but much less than the speed limit).

There are good reasons for improving public transport in Australian cities, but reducing traffic congestion isn’t one of them. Arguing that it will is little different from arguing that building motorways will solve congestion.

There’s (some) truth in the proposition that congestion charging should be accompanied by improved public transport, but by themselves trains, trams and buses aren’t “congestion-busting”. (1)

The other thing Ms Rice doesn’t appreciate is how costly and difficult it would be to build a fast, inter-connected transit system that’s attractive enough to pull drivers out of their cars on a significant scale.

Given Melbourne Metro is estimated to cost $11 billion for a mere 9 km of tunnel, retro-fitting a network that approaches the wonders of the London Tube or the Paris Metro in Australia’s expansive capitals would be extraordinarily hard. (2)

None of the political parties have shown how they would fund public transport on the “congestion busting” scale they say is necessary in Australia’s major cities (they all love to talk about metros!) while meeting all the other demands on government.

The cynical ease with which politicians grab any pretext to press the buttons that appeal to the reptile parts of their constituent’s brains is breathtaking. It’s not just the Greens either; sadly, they all do it. (3)

Very few politicians have any interest in addressing what really needs to be done to improve our cities; it’s too hard politically so they’re content to play with symbols (e.g. see Are politicians doing what’s needed to grow our cities?).


  1. I say some truth because most of the behaviour change from congestion charging would come by way of low value trips being rescheduled to off-peak periods (when there’s either no charge or it’s low) or not being taken. The equity effects should mostly be addressed by compensating low income travellers e.g. income supplement (but not via a concession on charges)
  2. Note that Melbourne Metro is a planned new west-south rail crossing under the CBD; despite the name, it’s not a metro (Bill Shorten, take note).
  3. I’m tempted to judge the Greens more harshly though because the party isn’t as constrained as the others by the objective of winning enough votes to form Government in its own right. It has a much narrower constituency and hence is better placed to advance a more progressive and realistic, albeit more painful, agenda for change.