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Analysis relating to peak car

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Last updated - Jan 2013

Pages in this series

1 - The idea of Peak Car

2 - Graphic analyses of trends

3 - More analyses of changes

4 - Attempt to forecast future car use

I wrote this material on peak car in 2012-13. Although the data is somewhat out of date now, I think the basic principles still apply.

Further analysis of trends

This page presents more analysis to try and make sense of some of the trends noted on the previous page.

Current car access levels for men and women

The chart below shows how the percentage of men and women with access to a car as a main driver aged 17 to 90 has changed during the various survey periods. In 1985/6 60% of men had main car driver access compared with under 25% of women. By 2008-10 the figures are 62% and 50%. While the level for men rose up to about 1996-98, for women it has continued to rise, but has slowed somewhat.

How access to cars grows up to age 40

The next chart shows the percentage of men and women with access to a car as a main driver, from 17 up to age 40, in each of the main survey periods. The lines become heavier and less dashed over time. It is very apparent that by 2002-10 the rates for men and women are not very different. (Similar analysis for 2008-10 shows them to be virtually indistinguishable.(See graph in new window)) The lines have steadily moved towards each other and it seems that we now have gender equality (in terms of gaining access to cars).

It's difficult to predict how these will develop, but it does seem likely that, for younger age groups, and carrying on into older groups in the future there is unlikely to be a gender difference - but we still have 50 years to wait before those aged 40 will be 90, so the chart above will be likely to show a higher average rate for men of all ages for a few decades.

At what age do people give up their cars?

The next chart is more complex. It shows, for men and women, for two different periods, the increase in the percentage who have gained main car driver access over the last three years. So the light blue line peak shows that for men who were 19 in 2005-07, 12% more had main driver access each year than they had when they were 16 in 2002-04. For this age group, none had access aged 16, but 3 times 12 (36%) had access in 2005-07. (They are a different sample of people, so this is what is called 'pseudo panel analysis').

What it shows is that up to the age of about 40 people are likely to gain main driver access, but after that time it stays fairly level up to around the age of 80, when people are likely to forego their cars. Within the limits of the accuracy of the graphs the differences for men and women are pretty slight, though by 2008-10 men seem to gain at a lower rate for many age groups, and especially in older age.

Age of learning to drive affects how much people drive

While many younger people haven't learnt to drive, or gained car access, they may of course do so at the later stage in life. But there is some evidence that the longer one leaves it before driving the less likely one is to take it up, and data shown below shows that it seems that the later one learns the less ones drives. In the chart each line shows people in a different age group - and the graph shows the annual mileage recorded (on average) according the age they were when they learnt to drive. So, as an example, the light green line at the top shows that someone aged 40-49 (when they were surveyed) would drive just over 10,000 miles per year if they learnt when they were 17, but about 7,000 miles if they learnt at age 28, and about 5,500 if they learnt at 38. Note that the red lines for those aged 20 to 30 show odd changes for those learning in their late 20s, which is probably due to very small sample sizes.

It is apparent that for all age groups this trend has occurred, and that anyone learning in their mid twenties is likely to drive about 30% less that someone who learnt in their teens. Why this is is not really very clear and could be down to a number of factors. I have tested this for men and women, and the results are similar, though somewhat less pronounced. (See male and female graphs in new window)) Since women historically tended to learn to drive later, and tend to drive less this could have been an explanation, but doesn't seem to be.

What does the future hold?

The next page explains my attempt to forecast what might happen under different scenarios.

Source - National Travel Survey from the UK Data Archive, with additional variables provided by the DfT National Travel Survey Team. The research for this has been done in relation to my Visiting Research Associateship with Transport Studies Unit in the University of Oxford. I am writing this up as a TSU Working Paper which I hope will be published in the spring of 2013.

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Gordon Stokes, 2013