'Peak Travel'

 A new paper suggests that the industrial world may be close to ‘peak travel’.(1) After a half a century of rapid increase, the number of kilometres travelled per person has started to slow down or even reverse in advanced countries. Car travel per person appears to have peaked at around 4,000 miles per year in Japan, around 7,000 miles in Europe and about 9,000 miles in Australia and Canada. The US, at around 13,000 miles per person, may be seeing a sustained fall.  While this decline is probably partly driven by rising fuel prices and economic stagnation, there is growing evidence of a saturation of the need for car travel. Similar results are seen for public transport and for domestic air travel – and indeed for freight transport. The implication is that the rich world may not have to choke off the demand for mobility by further huge increases in fuel taxes or road pricing because other forces are already depressing the amount of travel. (The authors don’t say this, but I suspect that their results would not be as striking if they had included international air travel where demand is still growing).  ‘Peak travel’ would be unambiguously good for emissions as about 25% of all CO2 emissions in developed countries arises from motorized travel and up to about 5% from air flights. Improved fuel efficiency in cars and the move to electric vehicles will cut fossil fuel use rapidly if the number of miles travelled continues to plateau.

 At first sight, the flattening of the number of kilometres travelled is surprising: most econometric models have shown personal transport demand continuing to increase for decades to come. These models are driven by the assumption that as people get richer they travel more. For example, the US Energy Information Administration’s model forecasts the number of miles driven using estimates of future growth in disposable income, fuel prices and demographic adjustments for the number of elderly people and females in the driving population.

 Similarly, here is the latest forecast from the UK’s Department for Transport. It shows a 43% increase from 2003 to 2035 in the number of vehicle kilometres.


England, Forecast Change compared to 2003 Year Traffic (Vehicle km) Congestion (Lost time/km) Journey Time (time/km)  
Central Forecast 2015 7% 6% 1%  
2025 25% 27% 4%  
2035 43% 54% 9%  

 Source: Road Transport Forecasts, 2009, UK Department for Transport

 The annual increase to 2035 is about 1.1% a year. This figure is consistent with the trends of recent decades (see below) and is used by the UK’s Committee on Climate Change in its central forecasts for the next few decades.

Historic Growth in Traffic, GDP and Oil Prices, Average Annual Growth

Decade Traffic Oil Prices GDP Comments
1950s 8.4% -0.5% 2.4% Strong increase in 1st car ownership
1960s 6.3% -3.7% 3.1% Strong increase in 1st car ownership
1970s 2.9% 24.4% 2.4% Oil Crises
1980s 4.7% -10.3% 2.3% Strong growth post 1982, falling oil prices
1990s 1.4% -2.9% 2.1% Early 90s recession, fuel duty escalator
2000-2007 1.2% 15.4% 2.8% Steady traffic growth, rapidly increasing oil prices

Source: Road Transport Forecasts, 2009, UK Department for Transport 

What is going on? Why are the traditional models of transport demand showing continued growth but actual distances travelled tending to plateau and fall? The authors of the paper speculate that the obvious reason is that most people don’t want to spend more and more time in cars or buses. The amount of daily time occupied in travel is, they say, about 1.1 hours and any increase is unwelcome to most people. And as congestion increases, the distance travelled in the typical 1.1 hours per day is inevitably tending to fall and we are now seeing that decrease in national travel statistics.

So it looks like the modellers had it wrong. Travel demand will probably not continue to increase because - unlike truly desirable activities, such as going out to a restaurant or buying nice clothes - most of us see travel as a chore not as a pleasure. Motorised transport is getting more efficient as fuel consumption is improving and the world  is switching to electric cars. Even if GDP continues to increase we may see a sharp decline in transport-related emissions.

(1)   Are we reaching peak travel? Trends in passenger transport in eight industrialized countries. Adam Millard-Ball and Lee Schipper, submitted to Transport Reviews.