Vehicle traffic grew at a fearsome rate worldwide for decades … until 2007. Then came the perfect storm of an economic collapse, a digital revolution and major changes to urban lifestyles. But is this just a blip?

A funny thing happened on the way to Carmageddon: the predicted traffic failed to show up. As engineers continued to forecast traffic growth in line with historic averages – up, up and yet farther up, to an eventual “carpocalypse” – actual traffic not only fell short of projections, in many places it just plain fell. A growing number of researchers and commentators are now suggesting that we’ve reached “peak car”, the point at which traffic growth stops, and potentially even falls on a per capita basis.

Total vehicles miles travelled (VMT) has been outpacing population and jobs for decades, across industrialised countries. For example, check out the US from 1960 to 2012:

Vehicle traffic grew at a fearsome rate, as any commuter can attest ... up until 2007. Then traffic not only plateaued, it fell. Similar trends are evident in the UK and other developed countries. Phil Goodwin at UCL has compiled statistics for various countries into the following chart:

The pattern is clear. The only uncertainties are about what caused it, and whether it will continue into the future.

And, as it turns out, there are fundamental disagreements on those points.



Most highway agencies appear to be adopting what Goodwin labels the “interrupted growth” hypothesis: because the downturn in traffic parallels that in the global economy, the bad economy is to blame for the motoring decline. Traffic growth will resume once there’s a global economic recovery, they predict. Backing for this view comes from data from the last two years in the US, where total VMT increased as the economy recovered and gasoline prices fell. The miles travelled grew by 0.4% in 2013, and 1.7% in 2014.

Others – often people who are also advocates for public transit, curbing sprawl and so on – attribute traffic falls to changes in society and consumer preferences, such as the increasing rejection of the car by young people. Supporters of this view see the current situation as peak car, and expect these changes to continue into the future.

The key point of debate is often less the forecasts than the policy response: how much public or private money to put into roads versus other transport?

In the US, less than half of eligible drivers in 2008 had a licence, versus nearly two-thirds 10 years previously

What’s frequently lost in the debate is that traffic experts themselves predicted a driving peak long ago. Models developed as far back as the 1950s and 60s anticipated that at some point the demand for driving would reach saturation point. A 1974 report in the UK predicted that point would be reached in 2010, a remarkably prescient view. As Goodwin points out: “In fact, the 1970s predictions were official government forecasts by its own research laboratory … The institutional memory collapsed and the generation who remembered or were involved in those forecasts is now only a few elderly specialists, like me. I was as surprised as anybody when I re-examined the old reports: I had no idea that the forecasts were turning out so accurate 30 to 40 years later. Mind you, that does not prove the method is right, of course, but it is food for thought and certainly demonstrates that the idea of eventual saturation is not alien.”

UCL’s David Metz, formerly chief scientist of the UK Department for Transport and author of Peak Car: The Future of Travel, has taken up the saturation theme. “Saturation of daily travel demand is to be expected and is a likely explanation for the observed cessation of per capita growth of personal travel.”



Metz believes we’ve entered a “fourth era” of travel. The first era was our roaming hunter-gatherer phase, the second era was our age of settled communities during which we travelled primarily on foot. The third age was the new era of speed and distance unleashed by the railways. The fourth age, Metz argues, is now dawning: one in which the per capita growth of daily travel “has ceased”.

Facebook Twitter Pinterest ‘We should expect the transformations unleashed by globalisation and technology to affect virtually every area of our lives - including driving’. Photograph: David Jones/PA Archive

Metz attributes this mostly to the diminishing marginal value of additional car travel now that we can move fast and far on mature transport infrastructure, like buses and trains. The amount of time people are willing to travel has been relatively constant throughout most of history: roughly an hour a day. As technology enabled us to travel faster, we were able to travel further within that travel-time budget, which vastly expanded the circle of possibilities open to us. Now that modern transport, especially roads and modern automobiles, is ubiquitously available, we have almost everything we need within our “travel budget”. Therefore, we gain little from more driving.

Consider the supermarket. Metz cites a Competition Commission finding that 80% of urban Britons have three supermarkets within a 15-minute drive, and 60% have four choices. Why drive more to get to more supermarkets when you already have three or four close by? It’s like this with many goods and services in our lives. In short, because we already have easy access to plenty of options, there’s little value to us in driving more.

(Not everything is like this, of course. Some things, such as a particularly good school, a world-class theatre, or specialised high-wage employment aren’t widely and evenly distributed. So people in places like London or Manhattan are willing to commute longer: New York has the longest commute times of any major US city … though still only just over 35 minutes.)

We appear to have reached the end of easy technical ways to travel faster. Even if high-speed rail were more widely deployed, train travel accounts for a minority of trips, and high-speed rail, as Metz points out, “a minority of a minority”.

In line with the saturation theme, it would appear that everybody who wants a car already has one: there are more vehicles than licensed drivers in the average US household, a figure that itself also peaked around 2007 and has started to decline.

End of the car age: how cities are outgrowing the automobile Read more

Beyond saturation of demand, there have indeed also been many social and technological changes. An ageing population means more elderly people who can’t drive. High youth unemployment in Europe may explain why fewer young people are getting driver’s licences compared to previous generations. Changes in lifestyle have also contributed. In the US, less than half of eligible drivers in 2008 had a licence, versus nearly two-thirds 10 years previously. And the overall percentage of the American population with a driver’s licence peaked in 2008.

We’re also living in a digital age. Online retailers like Amazon have eliminated many trips to malls and outlet stores. Online transactions nearly tripled in the last decade as a share of US retail – they are now at 6.6% and growing – and are growing at double digits in many European countries (20% last year in Germany). Broadband internet at home also means more telecommuting: the share of people working from home in the US has increased from 3.3% to 4.4% since 2000, and in the UK by 13% between 2007 and 2012.

It isn’t hard to see that all of these factors play a role in traffic changes. The highway engineers are probably on to something when they point to the economy, but there have been profound changes in our society, and we should expect the transformations unleashed by globalisation and technology to affect virtually every area of our lives.

How these changes will interact and play out into the future is unclear. But one need not believe that all 20-somethings want to live in a micro-apartment downtown with a folding bicycle to sense that the trend in driving may have fundamentally shifted.



“It looks as though the debate will run and run until eventually history decides,” Goodwin says. “Some people say it already has.”