1. Transport
August 18, 2015

Wealth and car use are no longer related variables. Traffic congestion is not coming for our cities

By Peter Newman

There is a new fear on the block in Australia. As well as ISIS, home invasions, wind turbines and the budget deficit, we’re told that now we must fear… traffic congestion.

The Infrastructure Australia report on the future needs of our cities emphasises the growing problem of urban traffic congestion all over the country. It is echoed by the State of Australian Cities report.

Congestion, it warns, will overwhelm our futures, making them unlivable, uneconomic and ungovernable as we fight for every piece of road space.

But do we have to accept that congestion trends will overwhelm us? Is it really right to fear congestion?

According to the IA report travel times are going to increase by at least 20 per cent. The total cost of such congestion will increase from A$13.7bn a year to A$53.3bn by 2031, an increase of nearly three times. The loss of time will apparently cripple us.

The public policy reaction to fear is to jettison economic analysis and throw money at it. No benefit-cost ratio is needed as we need to act now or it will overwhelm us. Kneejerk reactions like this are usually regretted in hindsight – but at the time we have no choice, it must be done.

In this climate of congestion-fear, big roads are not being assessed, just announced. The congestion peril is coming. We must honour the Abbott government’s election commitments to around A$40bn of high-capacity roads such as the East-West Link in Melbourne (now discredited and dropped by the Victorian Government), the Connex West system in Sydney (causing similar pain with communities subject to its impact) and, most recently, the Perth Freight Link (which looms as the biggest election issue facing the Western Australian government that never actually wanted it). All of these roads have benefit cost ratios that make them very questionable.

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Long-term plans are being drawn out of old cupboards for road projects dreamed up in the 1960s – like a plan to build a 10-km tunnel under Perth’s Swan River, to link the city’s leafy western suburbs with the similarly well-heeled area around Applecross. Good luck with that one.

Peak car

The congestion trends being used to scare us are not based on actual data, but on projections. They come from a model that is now discredited.

In reality Australian cities peaked in car use per person in 2004, regardless of their level of car use. (All developed cities across the globe seem to have hit such a peak at some point in the last 25 years.)


Peak car use in Australian cities. ImageNewman & Kenworthy 2015.

Around the world there is a new dynamic in our cities. The young and wealthy are moving back into cities, where they do not need to use a car; and they are preferring fast trains and buses over traffic, wherever they can.

Rail patronage is booming way beyond predictions, as the speed of rail leaves traffic behind. The table below shows the relative speed of public transport (bus and rail) to traffic: it’s gaining, but still loses to private cars. It also shows the relative speed of rail to traffic, which is now beating the traffic in all cities in our global sample.

Comparative Speeds of public transport (bus and rail) to traffic, and also rail to traffic, in global cities. Image: Newman & Kenworthy 2015.

Predicting the traffic

For decades the transport planning profession has used what is known as the Four Step model to predict traffic and hence provide road capacity. It does not suggest alternatives, such as public transport or land use changes, that reduce the need to travel: it simply suggests building more road capacity.

It has been put aside by most European cities, who quickly saw what it did to rip the heart out of American cities. But despite its obvious simplicity it remains one of the modernist tools that are used to explain the future of cities. Most of all it is a tool to create congestion-fear.

The Four Step model now has revealed one major failing: it assumes that, as wealth rises, then car ownership and car use will also rise. As the data above suggest, if we look to the future we can confidently predict that wealth will rise – but we cannot predict that this will automatically mean more car use. The two variables are now decoupling.

The young and the wealthy are buying locations where car dependence is minimised and where sustainable transport options are easily available. Freedom and connection is now based on smart phones and social media – and these are easier to use where you can walk, cycle or use a bus and train.

In the US, the cities that are decoupling GDP from car use the most are the cities which have invested in rail, such as Washington DC and Portland, as you can see in the chart below. In cities that are emphasising sustainable transport modes the economic benefits are increasingly being demonstrated (see also the book and this article by urban theorist Richard Florida). The knowledge economy requires dense centres and spatially efficient modes – walking, cycling and rail transit.


Decoupling wealth from car use in Washington DC and Portland, Oregon. Image: Newman & Kenworthy 2015.

This global trend is also not just a phenomenon of wealthy cities. Rail projects are dominating the transport agenda in China, where metros are under construction in 82 cities; and in India, where Prime Minister Modi has declared any city over a million needs quality transit and 51 cities are building metros.

Even if we were faced with a mountain of traffic congestion we should not be building high capacity roads, as they are no longer working to deliver the transport outcomes once expected. The Texas Transportation Institute has compared miles of freeway against delay in the top 20 American cities and found no correlation, as you can see in the chart below.


Freeways and delay in American cities. Image: Texas Transportation Institute, Urban Mobility Information.

The latest data on American cities shows that the top six most walkable cities have 38 per cent higher walkability. Australian cities have been showing this in their city centres as well (Gehl, 2011). This is now the real competitive edge attracting capital for the knowledge economy and to retain the young talent. This is how we should be facing the future – not quivering in fear about congestion.

It’s time to change our traffic prediction models.

It’s time to support global trends towards transit, walkability and urban regeneration.

It’s time to drop the big road fetish.

It’s time to stop fear of congestion as the core issue facing the future of our cities. The Conversation

Peter Newman is professor of sustainability at Curtin University

This article was originally published on The Conversation. Read the original article.

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