Why we need to manage transport demand

“Building more roads to prevent congestion is like a fat man loosening his belt to prevent obesity” said Lewis Mumford in 1955. New roads create traffic, and we have known this for decades.

There’s a pretty simple reason why. Every journey has a cost in time and in money. The longer it takes us to get somewhere, the higher the price we pay. If you build a new road or widen a highway to reduce traffic congestion, it lowers the cost of making the journey. The rest is basic supply and demand: lower the cost of something, and demand goes up. Here’s more from CPRE.

The phenomenon of new roads creating demand is called ‘induced traffic’, and it was first observed in the 1920s in Britain. Charles Bressey wrote in the 1930s about “the remarkable manner in which new roads generate new traffic.” This was not considered a bad thing. The motorway network was built in anticipation of a new motoring economy. Road building coincided with rail closures in the 1960s as a deliberate effort to encourage car ownership. Margaret Thatcher’s Conservative government explicitly linked roads and economic growth in a plan called Roads for Prosperity. Yes, roads create traffic. But more cars was good for the car manufacturers and hence the economy.

There was only so long that could go on for, as roads got busier and those blissfully empty motorways clogged up with cars. Air pollution worsened. Traffic moved through city centres at walking pace, but pressure was mounting for land and it was getting harder to build new roads.  In the mid 90s a national study concluded that there’s scant evidence that new roads boost economic growth, and that trying to ease congestion by building new roads is self-defeating.

Tony Blair’s New Labour party took heed, and came into office in 1997 as the first government with a policy to reduce car use. “Since new roads can lead to more traffic, adding to the problem not reducing it, all plausible options need to be considered before a new road is built” said a policy paper from 1998. Transport minister John Prescott began planning urban tram systems and discussing road pricing.

The new approach to traffic management lasted all of three years. Some within Labour worried that making car use more expensive would be regressive, pricing out the poor. Even more concerning was the media and popular reaction. The Conservatives accused Labour of being anti-car, and they were winning voters back over the issue. Fuel tax protests were the final straw, and sustainable transport was off the table again. (The story is well told in Jon Reeds’ book Smart Growth.)

Seventeen years later, we’re as wedded to car culture as ever, with even greater pressures on the environment. It’s well past time to talk about reducing demand again, and we can learn from Labour’s failure. Let’s make sure that public transport is affordable and desirable, so that getting people out of cars is a positive. Pricing poorer people off the roads would indeed be unfair. Let’s encourage car clubs and car-sharing, so that motoring remains accessible without being a default option. Let’s think creatively about planning, so that new developments allow for active forms of transport first. Congestion charging has worked in London and could work elsewhere. And most of all, let’s learn from the past and stop repeating the same mistakes, decade after decade.


  1. I fully agree with what you say but any Government will STILL face very averse reactions from much of the media and public, even if public transport etc is improved. So it will need a plan to deal with the media BEFORE implementing policy changes. Can we help them?

    1. Yes, and this is where we need to learn from Labour. I think there are a couple of ways to do that. One is to give people travel alternatives before you start disincentivising driving, and work on a long term strategy. If Labour had proven their case with high quality public transport in their first two or three years in office, and then brought in measures to tackle car dependency in a second transport bill, it might have been different. Mind you, it was the fuel duty escalator that killed Labour’s plans, and that was a Conservative idea from John Major’s government. Cross-party working would be sensible, in order to carry a long term strategy through and not have it derailed by an incoming government.

      Second, governments could link any taxes or levies from driving or fossil fuels directly to sustainable transport investment. That addresses the idea that the government is out to ‘punish’ drivers, or is tapping them for cash. Governments would always prefer to put everything into one pot rather than tie revenues to particular outcomes, but it creates a narrative: this 1p on every litre of fuel is paying for your city’s new tram system, or whatever.

      Finally, it’s always going to be better to undermine the status quo with something better, and I think car ownership could be an interesting strategic target. If governments encouraged car clubs, with EVs or hybrids of course, they could fly the flag for ‘mobility’ and access to a car, but without the expense of owning and maintaining one. All the evidence suggests that when people have a car on their driveway that’s theirs, they’ll consider it their default transport method and drive it all the time. If they have access to a car but have to pay each time, they’ll drive less.

  2. The process apparently works in the other direction as well. An effective system of congestion charging is needed to manage demand, possibly on the lines of the proposed Cambridge scheme. This failed because the technology was not up to the task in 1990. It is almost certainly practicable now.

  3. Stuttgart has just started to introduce a rather small scheme in one area to encourage people to leave their cars and use public transport:A new business district will have minimal parking but good public light rail and bus connections.

    The howls of motorists can be heard from our village.

    Sometimes I think motorism is a new religion: cars (known as “Mobility”) are the new god,or possibly motorists. Roads are sacred ground and heretics are people on bikes, walking or public transport. Or trucks. Anything that motorists perceive as encroaching on their sacred ground is denounced with the fervour of a revivalist preacher in a tent. Sometimes it seems like the language is the same. New technology presented as the great Revival which will reward the faithful, and heaven, well heaven is the situation in the adverts of sleek cars driving down empty roads. This is what we must aspire to, and it becomes the basis for more road building…

  4. It’s interesting how emotionally charged car culture is. It does get extreme reactions, but then driving provokes extreme reactions in people too. I wonder if it’s the illusion of private space. When we’re in our own vehicle, warm and comfortable, with our choice of music and so on, it’s easy to forget that the roads are actually a public space.

    When we’re in a private space we feel at peace, and entitled to do as we please. And then another driver cuts in front of us or drives too slowly, and it confronts that sense of entitlement and shatters the idea of private space. And so we get that simmering impatience that any driver will recognise, or at it’s ugliest, road rage.

  5. If we had any sense at all we would abandon this deadly car culture this minute. Period. But we don’t. The real trouble holding back any progress in our society lies in the total inability of the masses to see beyond their immediate, particular interest. Urgency always beats importance. That the car slowly kills (and sometimes not so slowly) doesn’t quite register with the public: it is too abstract a concept for most to grasp. So all policies shall need to contend with deeply ingrained prejudice, and fear of losing out on sacred convenience. That’ll always be the main hurdle to overcome.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: