Myth: Freeways are cheap, and public transport is expensive by comparison

Fact: A two-track railway costs around one-third as much as a six-lane freeway, but can carry more than three times as many passengers. Public transport is one of the most cost-effective ways yet known to move the large numbers of people wanting to travel in an urban area.

The fact that large road proposals in Melbourne almost always get funded, while large public transport proposals never do, can lead people to think that roads are funded because they’re cheaper. The bureaucracy encourages this view by emphasising the costs of public transport proposals and the benefits of freeway proposals.

These days, economists maintain the role of fun police by pointing out to people that there aren’t any free lunches…. Except, of course, when it comes to building roads. In this country, we seem to assume the billions we spend on roads each year most certainly could not be spent on hospitals or schools. The money could not be spent tackling climate change and it most certainly could not be spent on public transport. While the economics textbooks don’t have this chapter in it, most politicians know that road funding is ‘different’.

—Richard Denniss, Economic road map failure, Canberra Times, 8 July 2011

The Victorian transport bureaucracy’s fast-and-loose approach to spending money on roads is deservingly satirised in Wayne Macauley’s novel Blueprints for a Barbed-Wire Canoe. The novel’s premise is a fictional planning proposal by which an estimated 990 people are to be lured to a new housing estate by the promise of a 50-kilometre, six-lane dedicated freeway. Were such a road to be built today, its cost would amount to over $1 million per resident! (Alas, in the novel the road lobby loses its nerve and the freeway doesn’t go ahead.)

In reality, the capital cost of freeways is vastly greater than that of the rail infrastructure required to move the same number of people. A case in point is Eastlink, which cost $2.5 billion for some 45km of road, or a massive $55 million per kilometre. More mundane freeway projects have costs in the vicinity of $30-40 million per kilometre for a six-lane road.

We cannot rely on Melbourne experience for accurate costings of rail lines, since the last major urban rail extension completed in Melbourne was the Glen Waverley line in 1930. However, Perth is currently undergoing a renaissance in urban rail, and we can use their costings as a benchmark. The Northern Suburbs line, built in Perth in 1991, cost $230 million all up for 33km of track, or $7 million per kilometre – including earthworks, track, overhead lines, stations, associated roadworks, and rolling stock. Perth’s new southern railway to Mandurah was built for $12 million per kilometre, including the cost of freeway realignment and tunnels under Perth CBD. Excluding the latter, the cost of earthworks, track, overhead, stations and road overpasses for the 70km surface railway was $422 million, or just $6 million per kilometre.

But how does the capacity of a freeway and a railway compare? The carrying capacity of a freeway lane is roughly 1800 vehicles per hour, or 2000 people per hour given average vehicle occupancy of 1.11 passengers. A typical six-lane freeway therefore carries up to 12,000 people per hour in both directions. (Another page explains why car pooling can’t be relied on to boost this figure by much.)

A double-track suburban railway, meanwhile, can easily support one train movement every three minutes in each direction without straining its capacity. A six-car train can carry around 1000 passengers before reaching crush conditions. Thus the rail line can carry at least 40,000 people per hour in both directions, and perhaps more depending on the signalling system and vehicle design. (A similar calculation can be made for freight capacity, with much the same result.)

As a living example of this basic observation it is worth considering the Sydney Harbour Bridge, which carries both road and rail traffic. In the morning peak, according to NSW Transport figures, 22,600 people are carried in two hours on the single rail line in the peak direction. A similar number of people are carried in buses on the adjacent bus lane, albeit more slowly. Then there are five lanes for peak-direction car traffic, which between them carry just 15,400 cars between 7am and 9am (or about 17,000 people at average occupancies). In other words, cars carry around 27% of the peak hour passenger load on the bridge but take up 70% of the space.

What all this shows is that roadways for private cars are one of the most inefficient forms of transport infrastructure, particularly when compared with railways and tramways. One more example, this one from overseas, was pointed out in a 2009 op-ed piece in the New York Times. In 1907, writer Robert Sullivan reminds us, the Brooklyn Bridge in New York carried 426,000 people per day – most on trains, on horse-drawn trolleys or on foot. After World War II, the train and tram tracks were removed in order to make more room for cars (just as the Sydney Harbour Bridge’s two tram tracks were removed around the same time). As a result, by 1989 there were 178,000 people crossing per day – and nearly all of them complained about the traffic congestion.

We conclude that by comparison with a six-lane freeway, a two-track railway costs around one-third as much but has more than three times the carrying capacity. Of course, the railway also takes up far less space (typically requiring only a 10-metre reservation compared with 50 metres for the freeway), inflicts far less noise on nearby residents, and generates virtually no pollution. (Even the greenhouse emissions can be minimised by buying the electricity from renewable sources.)

However, as we explain on another page, it is in the interests of the powerful Melbourne road lobby to make public transport projects appear more expensive than they are. Privatised operators and suppliers also find it in their interest to inflate project costs, as it boosts their prestige to preside over a big-ticket project, and perhaps because of the old rule that the more money there is floating around, the more likely it is to wind up in one’s own pocket!

Last modified: 11 July 2011