Monday, February 6, 2012

Lies, Damned Lies, and Cycling Statistics

A strangely incoherent article from Andrew Gilligan in the Telegraph today. He tries to argue that cycling is getting safer in London, and this "fact" is inconvenient to those who want to blame Boris Johnson. Unfortunately, the statistics he uses don't match his argument. Whatever his argument is. See if you can figure it out, and if you can, please let the rest of us know.

Gilligan starts off:

"It’s certainly hard to think of any policy area where official interventions have been so inept."

Right there with you so far mate...

"The vast majority of British cycle lanes are either totally pointless or actively dangerous."

Sounds familiar to most go on...

"As a 100-mile a week London cyclist myself, I travel every day through places where TfL should do more."

Should do more? Is that the same as "inept and actively dangerous"?

"But 'carnage' there is not."

Maybe you'd like to define 'carnage' for us Andrew? As the Times points out, over 27,000 cyclists were killed or seriously injured in the UK over the last decade. I guess that must be a teddy-bears' picnic, not carnage. But irony aside, road collisions are the leading cause of death for young people, and cycling is the second most dangerous mode of road transport, after motorcycling. Nationally, at a time when the overall casualty rate for road transport is going down, the rate for cycling is going up. How is that not cause for concern?

"to say that the deaths 'went up by 60 per cent' last year, as various bloggers and journalists keep doing, is narrowly right – but broadly misleading."

Maybe you'd like to visit the bereaved partners, family and friends of that 60% - it's only 6 people after all - and explain that they've been mislead? The point surely is, those deaths should not be in vain. It seems to me pretty callous to suggest that we should do nothing about Kings Cross or the Bow Roundabout, when those locations (among many others) are 'actively dangerous' in Gilligan's words, and have been assessed as being so by TfL's own consultants.

"Allowing for the rising number of trips, the trend [in serious injuries per 100,000 trips] is, as you can see, clearly down."

What?? Down over what period? The figures Gilligan quotes are as follows:

2002 0.36
2003 0.36
2004 0.28
2005 0.25
2006 0.24
2007 0.29
2008 0.27
2009 0.24
2010 0.26

Gilligan says it would not be valid to compare two years. He doesn't tell us what he is comparing though - he just says the trend is down. While there was a downward trend until 2006, since then (as you can clearly see) the figures have gone up and down in a pretty unpredictable manner. In fact, averaged since 2004, the injury rate on the same basis is 0.26 - so the 2010 figure is the same as the long-term average since 2004. Does that look down to you? And remember we're talking about a casualty rate per trip set against a background of rising trip numbers. In that time the number of deaths and serious casualties has climbed from 340 to 467. If those trends continue, it's likely that one in three people killed or seriously injured in London in 2025 will have been riding a bike. Would that qualify as 'carnage'?

"I’m sorry if that doesn’t help the people trying to diss Boris Johnson, but there it is."

On this blog, we're not trying to 'diss' Boris in particular (you're so 'down with the kids', Andrew. I thought the Telegraph was a quali'ee newspaper).  We're totally equal-opportunities in our dissing, y'get me? We're also not driven by statistics. We're driven by the desire to do something about the needless human cost, by the knowledge that our city could be so much better if more people cycled, and by the awareness that the reason more people don't cycle is not because of statistics but because of the all-too-obvious dangers that anyone can witness if they venture very far on a bike. And Boris has done next to nothing to alleviate those dangers (not that Ken Livingstone's record is much better).


  1. Consider also that in NYC the rate is decreasing

    Given the cost of NYC interventions vs the blue paint, the cost effectiveness of the london actions have to be considered too.

  2. I was a bit miffed by his apparent use of the stats aswell, just saying that usage has gone up so you should expect accidents to increase is rather poor. Hasn't car usage also gone up yet the accident rate here has gone down. A trend that I'm sure will continue on as manufacturers produce more reliable safety systems to mitigate human error, cars nowadays come with an array of gadgets including ABS brakes, traction control, electronic stability control, automatic braking etc. which older cars didn't benefit from. Yes it makes them "safer" but I'm sure it also encourages drivers to behave more aggressively as they know they think they can trust the car to sort it out when it all goes wrong....

  3. @Mark - indeed, there is considerable evidence that safety improvements tend to get consumed as performance benefits. See

    Also, fewer 'accidents' doesn't mean less danger.