26 November 2009

Lancet figures it out: less cars, more bikes, more eating out

The Lancet medical journal has just published a series of reports on climate change. One of them deals with the health benefits of reducing vehicle use, and a few newspapers (such as the Telegraph) have tried today to summarise their findings.

Don't believe figures you read in papers by pressurised journos speed-reading the report. They're rubbish at stats. Never get a journalist to work out the restaurant bill unless it's on their expenses. Because this report is crammed full of them, as well as tables, footnotes and caveats. It wisely gives no simple headline numbers. Wading through it is like trying to cycle up Kennington Road at rush hour with all those roadworks.

But the bottom line, unsurprisingly, is that many lives would be saved, and many more years of health enjoyed, if more people walked and cycled and fewer went by car, thanks to reductions in everything from respiratory problems to depression.

However, figures help focus the mind. And their best-case assumption, as far as I can make out, reckons on 500 premature deaths per year in London being avoided, and 7300 extra years of health per year per million population (in other words, I'm assuming, two and a half extra days of good health per person per year; I'll take it as a long weekend in July, thanks).

But don't trust my arithmetic. Read it for yourself, if you have little on at work today. (I once did a degree in maths, so I'm rubbish at numbers. I can only remember my x times table now. Never get a mathematician to work out the restaurant bill, unless the local currency happens to be pi.)

Anyway, their best-case assumes cycling increases eightfold to match that in Copenhagen, Delft, Freiburg etc. Um, right. That's a big if. Though as they point out, it's from a low start: 55% of London car journeys are under 8km, so there's plenty of scope for increasing bike trips. (They also imply that in this scenario, cycling and walking accidents might increase by up to 40%, though the rate of accidents would reduce.)

All of this, though, needs "prioritisation for people who walk and cycle, and restriction of car travel to ensure active travel is the safest and most convenient, pleasant, and quickest way to reach destinations. The reallocation of space to provide a high-quality streetscape that is designed to meet the needs of pedestrians and cyclists is of particular importance."

Oh no! If that happens we'll have nothing to blog about. And I'll end up spending more time trying to work out restaurant bills.


  1. So you have a Maths degree! Really, I should have guessed. Cycling buffs are some of the absolutely geekiest people you could ever meet.

    Not just cycling wonks either, in fact all the green types I've met are complete and utter science nerds. I don't understand how they have this reputation as lah-lah-homeopathic-daisy-picking-softies.

    Not that I'm the *least* bit like that myself you understand.

  2. Yeah but he also has a degree in music.

  3. Hah! That just confirms it.

    I played a lot of gigs at one time in my life and then almost took a music degree myself (I did 2 years before the money ran out). In my experience musicians are at least as nerdy as scientists. In fact I'd say Music is sort of the humanities equivalent of Physics.

    At least he's not a jazzer - I asssume (although with the Goldsmiths involvement you can't be sure). They are particularly bad - always ready with a quick shot about modal interchange or majorminor sevenths (or is it minormajor, I forget).

  4. Well, yes, it's true, and it all goes to show the famous link in abilities between the two subjects. Cos I'm a bit rubbish at music too.

  5. This comment has been removed by the author.

  6. Great information about the cycling