Alongside Barry Hutton’s excellent “Planning Sustainable Transport” (also by Routledge), this is in the small but important list of “books which changed how I think about transport” and worth reading several times over. The author, David Metz, has spent his career at the Department for Transport and in various academic research positions, so he is able to explain authoritatively what good transport policy looks like. 

In short: people only have 24 hours in a day, and we spend on average one hour of that time travelling. Of course, there are age related differences (children and elderly people average 45mins a day), gender differences (men typically travel longer than women) and regional variations (Londoners in their 20s average 90mins/day).

But what’s surprising is that travel time averaged over the whole population hasn’t changed in more than 30 years, despite rapid changes to everything else from working patterns and population age profile to levels of car ownership. The proportion of income spent on travel has been relatively constant too, at 3 to 5% of non-car-owning households rising to 10 to 15% for those with a car (regardless of how many cars per household!) What has changed is the distance travelled: an inexorable rise from 4500 miles per year in the early 1970s to more than 7000 miles a year in 2007.

This means that transport planning based upon the idea that you are saving travel time is daft. All you end up doing is inducing more travel: the Newbury bypass (famously protested by Swampy and his pals on the basis that concreting over the countryside to reduce congestion and travel times was untenable) proved Swampy right in the end. After the new road opened in 1997, the total traffic volume (bypass plus the old route through the town) rose by a huge 50% in just 6 years. The traffic rose 3 times faster on the new road than the surrounding region (14%) and observed traffic flows were double what the traffic model forecast when planning the road.

This suggests that engineers have fundamentally failed to understand how induced traffic works: if you reduce the time taken to travel a distance X, you enable people to travel further in the same time. You will therefore increase access (more shops, workplaces or leisure opportunities within an hour of home) but you will not create more time, just more traffic as people change their destinations to match the new opportunities available. You might like to refer back to Laura Vanderkam’s advice on how to make best use of the 168 hours each person gets every week!

If the overall effect you are aiming for is less air pollution, you need to make travelling further unpalatable. That means if you get 10% more people on their bikes or on the bus, you need to make sure that the extra road space (and parking space!) is dedicated to bikes and bus lanes. Without “locking in” your gains, everyone else will just drive 10% further because they can (ie they got to their destination faster and hence over time they go to more places). Increasing speed means longer journeys, resulting in more noise, air pollution, road accidents and carbon emissions.

It is therefore crucial to make a distinction between transport policy measures that have the effect of increasing average speeds (eg building a new road, making trains run faster) snd those which don’t (eg providing segregated cycle routes, more frequent buses or longer trains with more seats).

Traditional transport planning also completely ignores the idea that the journey itself may be part of the point, not just the destination. One day recently, I walked to the local shop more because I wanted to get out of the house and admire the trees coming into leaf and the snowdrops starting to appear than because I needed anything in particular. The day before, I cycled into town for similar reasons: I had errands to run, certainly, but I chose to do them on a leisurely Saturday morning rather than in my lunch hour because I wanted to get out and about. This implies that green space and journeys which are enjoyable and healthy should be a critical part of transport planning.

See also:

  • ICE Podcast: How do cycling rates vary for different groups of people? Dr explains how to make cycle routes work for everyone, especially women, children, elderly and disabled people. For example, segregated cycle routes make a big difference, while mad “cyclists dismount”/”pick up your bike and carry it up the stairs” obstructions can make mass cycling nearly impossible. It also highlights the social benefits of cycling for being able to get out and about, especially for those with mobility problems (most people can cycle much further than they can walk).
  • Campaign for Better Transport’s “Roads to Nowhere” campaign, which challenges the assumptions behind building more road space.
  • London’s recent assessment of the health and congestion-related benefits from encouraging more active transport in the city (an estimated benefit of nearly £2.2billion per year!)

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