When an exasperated Professor of Transport Policy, Phil Goodwin took to the stage for his inaugural lecture at the University College London, with a lecture memorably titled, Solving Congestion (when we must not build roads, increase spending, lose votes, damage the economy, and will never find equilibrium), he took a well-aimed swipe at the ignorance about traffic which circulates as knowledge.
In the past 30 years this summary still stands as a piece of sense in a sea of rhetoric and exaggerated claims about the role of roads in the economy. As the news of plans to complete Cape Town’s (in)famous ‘unfinished’ freeways make headlines, yet again, it’s worth revisiting four well-researched truths about traffic:
- Roads generate traffic.
The best metaphor for this research is of the fat man (traffic) with a tight belt (roads). Does adding a notch or two solve the fat problem? Does keeping the belt tight make the fat man more or less likely to stay fat?
We know from research that in urban areas adding more roads simply feeds a culture of more and more car use. It does nothing to constrain that appetite for car travel.
2. Roads do not solve congestion.
Loosening the ‘belt’ (adding more roads) does, for sure give some immediate relief. But in the long term road-building generates even more traffic and the early-year benefits are quickly eroded. We don’t have to look further than Hospital Bend in Cape Town to see how quickly gridlock has resumed after the supposed relief of the additional lanes built at great expense to the tax-payer.
On a larger scale the freeway city of Los Angeles, which suffers almost perpetual traffic congestion, should be a warning against the pursuit of road building policies in urban areas.
3. Travel behaviour is a process, not a state.
Instead of thinking about fat men in tight belts, the metaphor transport planners use is that traffic is like water: It flows in pipes (roads). Improving the flow means diverting the water into more and faster pipes (roads). But people are not water molecules. They are not the same.
Witness the impact of Uber on attitudes towards car ownership. What difference would Uberpool and other car share schemes make to how cars are used and to traffic flows?
4. Road building kills public transport.
Public transport provision is a tricky, marginal business. It needs lots of people travelling on it to be viable. Public transport can quickly enter downward, or upward, spirals. In the upward spiral, more people travelling means that more buses are required, which means a more frequent service, which makes it more attractive to more people…and so on. In the downwards spiral the opposite becomes true. So road building and public transport are linked. And investing in roads reduces the viability of public transport.
And yet still road building is a force to be reckoned with. The question is why?
I think we are more deeply steeped in a culture of speed than we dare to imagine. And when speed is god, then roads and cars are the answer.