Amid all the trials and tribulations of Britain's troubled transport system, one thing apparently remains constant: the amount of time that people spend on the move. A recent report by David Metz, former chief scientist at the Department of Transport, shows that time spent in transit has not changed significantly for at least 30 years. On average, people spend around an hour a day travelling and make about 1,000 trips a year. The same was true in the early 1970s and there has been little variation since then. The data is taken from the annual National Travel Survey, based on the diaries of a representative sample of several thousand people. But beware media distortions biased by London commuters.
What has changed is that people now make longer journeys by faster means. The long-term trend is away from the slow, local modes such as walking, cycling and taking the bus, towards faster, longer-distance transport, mainly by car. Average distance travelled has increased by more than half since the early 1970s. We are going further afield for similar purposes: commuting further to work, shopping out of town, sending our children to more distant schools, taking our leisure at a greater distance from home, and so on. These trends have been reinforced by public policies that support dispersed residential and commercial developments and by the centralisation of public services such as health and education.
Metz suggests that you can't stop people moving. Mobility, he says, is fundamental to human nature, and derived from our evolution as hunters, gatherers, herders and migrants. The ability to run long distances distinguishes humans from other animals. Sweat glands allow us to outrun deer and antelope, which lack such a cooling mechanism.
If all this is true, we have got our transport policies wrong. Most transport projects, such as road widening, are assessed according to the total improvements in journey time they produce, aggregating the seconds saved by each traveller. It appears, however, that people do not value saving a few seconds or minutes, and instead choose longer journeys. Conventional economic analysis may therefore place too much value on marginal travel time-saving.
People derive benefit from travelling faster not so much because of the time saved, but because of the greater distances they can cover. The unintended consequences - traffic congestion, pollution, noise, danger and disruption, as well as social exclusion for those without access to cars - tend to be made worse by projects designed to improve the efficiency of the transport system.
Metz suggests that we should therefore pay more attention to policies which might slow things down, such as traffic calming or reducing the road space available for cars. There are some good examples. In London, Mayor Ken Livingstone has created a network of bus lanes, taking space away from cars. Hull City Council has introduced 20mph zones in residential and shopping districts, covering more than a quarter of the city's road length, and dramatically reduced road casualties.
Unlike many big road and rail schemes, these relatively small-scale measures can be highly cost-effective. New research by the London Road Safety Unit estimates at about £200m the cost of a traffic-calming programme to cover 60 per cent of local roads in London. It would pay for itself in less than a year through road casualty reductions: more than 50 fewer deaths, more than 1,000 fewer serious injuries and nearly 8,000 fewer slight injuries.
The other side of the equation is to reduce the distances that people need to travel. Transport is a product of where homes, businesses, shops, schools, surgeries, hospitals, leisure facilities and other services are located. Compact developments that combine high densities with mixed uses can make slower means of transport such as walking, cycling and taking buses and trams more possible. The message of Metz's analysis is: "Slow down, you're moving too fast."
Tony Grayling is an associate director of the Institute for Public Policy Research. Travel Time Constraints in Transport Policy by David Metz is published by Population Ageing Associates