Better cities: Myths surrounding great urban choke
Source: The Australian
Author: Ean Higgins
29 April, 2017
The problem with a whiz-bang new city road, any urban planner will tell you, is “if you build it, they will come”: roads are just magnets for more and more cars.
Politicians, particularly come election time, will promise an underpass, or maybe an overpass, a tunnel, a bridge or an urban freeway, saying it will ease congestion and reduce commuting times.
It’s the biggest political fiction of all time, says the Committee for Sydney, a progressive think tank and lobby group funded mainly by a wide range of businesses as well as not-for-profits and individual members.
“It is common for road projects to attribute up to 80 per cent of their benefit to reductions in travel times,” the committee says in a report entitled A Fork in the Road. “These reductions don’t actually accrue in practice.”
All the evidence in Australia and overseas shows that after a short period where traffic flow improves, more people decide to commute, more cars take to the new road and the journey takes the same or an even longer time.
In a paper called The Myth of Travel Time Savings, British transport planning guru David Metz suggested it was amazing politicians had got away with it so long, saying it was “surprising that it has been possible to value a phenomenon not empirically demonstrated to exist”.
It has taken decades, but a big change of thinking is in play.
The Committe for Sydney and its southern counterpart, the Committee for Melbourne, have decided to expose publicly the myth that new roads are the answer to traffic congestion. They say, instead, the way forward involves public transport projects.
With varying degrees of assertiveness, they also will promote the politically unpalatable policy of making those commuters who still insist on driving pay handsomely for the privilege.
“You cannot reduce congestion in the modern city by building or widening roads, this just generates new traffic: it’s called induced demand,” Committee for Sydney chief executive Tim Williams tells Inquirer.
“Academics are more or less agreed on this but the news has been slow to reach politicians and those appraising infrastructure projects.
“Only road pricing plus extra public transport capacity can reduce congestion: the jury’s in.”
The tone sounds much like the sort of thing the Greens would espouse, but for the business community the message has a lot to do with the huge loss of productivity that the problem represents.
One estimate put the cost of congestion at $16.3 billion nationally in 2015, and it is forecast to grow by 5.5 per cent a year between 2016 and 2030.
The Committee for Sydney report on the topic is comprehensive and persuasive, quoting examples from Australia and around the world.
“Wherever supply-side strategies have been attempted, it has been shown — and not just academically but in the lived experience of commuters — that if you build it, they will come,” it says.
“Over 10 years ago, a compelling review of dozens of transport studies concluded that, on average, increasing a road by 10 per cent immediately increases average vehicle travel by 4 per cent and that this reaches 10 per cent — equalling all the new road capacity — within a few years.”
The dynamic is that a new road will encourage more drivers to take it rather than alternatives including public transport.
That’s in the short term: the longer-term effect is that, combined with fearfully high housing prices in inner suburbs, urban workers see the new road as enabling them to commute by car from farther out where housing prices are lower, thus encouraging an ever expanding urban sprawl.
The process becomes a vicious cycle as politicians then have to promise yet more roads because commuters in mortgage-belt marginal seats complain of congestion.
Sydney’s M5 motorway, a 38km route built in sections starting in 1992, initially sharply reduced the travelling time from the CBD to the southwest, mostly by tunnelling under congested suburban roads and coming out in what was then countryside.
But it encouraged commuters to live farther out, helping create massive new suburbs where open country lay before, progressively extending the fringe of the greater commuter belt with more commuters and more traffic. Now the M5 is heavy with traffic for most of the day and night, sometimes becoming a parking lot at peak times.
So, what’s called the “M5 duplication” is under way to again increase the capacity for more cars by building another M5 beside the old one. That’s part of the controversial $17bn WestConnex project due to be completed by 2023, to which the federal government will contribute $1.5bn.
Based on experience, all this money will reduce congestion a bit at the start, but then commuting times will fall back to what they were as the new roads attract more cars and new outer-outer-outer suburbs.
“The evidence is that road expansions tend to reduce congestion only in the short run and that this benefit tends to decline over time as generated traffic fills the additional capacity,” the Committee for Sydney report says.
Australia seems to be one of the few advanced countries left that has not worked this out.
“Since the 1990s in the UK, transportation planners making business cases for road investment have to make due allowance for the full impact of induced demand on claims for travel-time reduction arising out of that investment being sought,” the report says. “In the UK, cost-benefit analyses must assume that average trip length will increase just as much as speed increases.
“By contrast, business cases and appraisal methodologies in NSW still overwhelmingly stress congestion and travel-time reductions as the key outcomes claimed for road investment.”
The interesting thing is that the induced demand principle also works in reverse: reducing road capacity does not necessarily increase congestion; people find different modes of transport, travel at different times or go somewhere else.
“The most prominent international example of this effect occurred in South Korea, with the removal of the Cheonggye Freeway in 2003 that had previously carried 168,000 cars a day into Seoul,” the Committee for Sydney report says. “In the place of the freeway, a nearby river was restored and a park created, coupled with new investment in a bus rapid transit service. The result was higher economic activity, greater urban amenity, higher land values and lower congestion.”
The report says a good test case in Australia was the brief closure of the Brisbane Riverside Expressway, when it was shut for three days in 2006.
A study found that affected commuters opted for a combination of changing their route (50 per cent), time of travel (40 per cent), mode of transport (15 per cent) or destination (10 per cent).
This goes to the broader point the Committee for Sydney makes: congestion is as much to do with human behaviour and motivation as it is with the roads themselves, and if you want to reduce congestion you have to provide incentives and penalties to change behaviour. And this is where the Committee for Sydney — and in a more timid fashion the Committee for Melbourne — wants state politicians to do something widely regarded to be political suicide: make motorists pay.
The Committee for Sydney describes it as “the key point of this paper”: “In attempting to regulate or reduce congestion in a city, success lies not just in increasing supply of transport infrastructure but in managing demand … all roads do indeed lead to a discussion about pricing.”
Pricing can mean quite a few different things, but the option favoured by the purists is a congestion tax. London introduced one, the nuclear option when it comes to getting people off the roads and on to public transport, and it initially reduced car numbers by 15 per cent.
The scheme imposes a £10 (about $17) daily charge for driving or parking a private vehicle within the charging zone between the hours of 7am and 6pm from Monday to Friday. Revenue raised through the London congestion charge must by law be invested to improve transport in London.
In the first 10 years the London congestion charge raised £2.6bn, of which just under half was invested in public transport, road and bridge improvement, and walking and cycling schemes.
There are variations of the concept; rather than cordon-based, another option is distance-based, charging for distance travelled by the electronic tagging of vehicles.
Both the Committee for Sydney and the Committee for Melbourne talk about a congestion tax.
“In the context of Victoria, this mechanism could provide an opportunity to influence the behaviour of private road users … this would generate a significant amount of revenue which could be specifically targeted towards a defined program of public transport investments,” the Committee for Melbourne says in a discussion paper called Moving Melbourne.
But the Melbourne lobby group baulks at calling for it outright.
“We have not been as positive that this is a solution, but we say, don’t reject it out of hand, you need to look at it seriously,” says Committee for Melbourne chief executive Martine Letts. She says the concern is to make any congestion tax fair, to develop a political support base for it.
“The community needs to be brought along for the ride,” Letts says. But her Sydney counterpart, Williams, a former top adviser to British cabinet ministers on urban renewal, is assertive that it can and should happen.
“I can see no alternative to a users pay per kilometre travelled basis, possibly with freight carriers and company cars paying more and general motorists less,” Williams says.
“There could still be extra charges on entering congested zones even under a general road pricing regime, so that would mean kilometres travelled plus congestion charge.
“Road pricing deals with the income needed to build and maintain roads in the future, and congestion charges deal with congestion issue. I think the trend will be towards road pricing of all vehicles in all parts of a state or national network.”