Just another accident statistic?

The recent spate of horrific cycle accidents in London, many resulting in fatalities, has focused attention on the perils of cycling on London's busy streets. There has been understandable grief, outrage and a rising political temperature as Mayor Boris Johnson is accused of 'blaming the victim'.

What there hasn't been (as far as I have seen) is any assessment of how dangerous cycling is in proportion to the number of cyclists, or compared to other forms of transport on London's roads.  It may seem a callous question to ask, as one cyclist crushed by a lorry is clearly one too many, but I was curious about the relative risk.

After not much digging in the London Datastore, I found some statistics from TfL's Transport Trends survey, which reports on number of journeys taken on different forms of transport each day (strictly speaking 'journey stages' - if I walk to a bus stop, take a bus, then cycle, I have had three journey stages), and the number of accidents and deaths suffered by users of each form of transport each year.  Oddly, the last set of numbers are for 2009 for journeys and 2010 for accidents, but I suspect the ratios did not change dramatically between those two years.

Here are the statistics:

The difference between relative accident rates is pretty stark.  London's cyclists are eight times as likely to be fatally injured as car drivers and passengers, and seven and a half times as likely to be injured.  Cycling isn't as dangerous as riding a motorbike (more than 50 times the risk of driving a car), but it's substantially more dangerous than walking or using other motor vehicles.  It would be interesting to extend The Economist's comparison of USA and Netherlands fatality rates, but I don't have the data. 

Overall, cycling on London's roads is about five times more risky than the norm for fatalities, and 10 times more for injuries.  I'm not sure whether I expected this to be higher or lower; by way of comparison, occupations such as roofers, electricians and farmers have similarly heightened fatality rates.  But it's not encouraging me to get on my bike.