Saturday, 24 November 2012

Map of 2001-2011 population change in London

Update: Those intelligent people in the Intelligence team at the Greater London Authority have now made a better map of population change between 2001 and 2011, which I think you should look at rather than mine (there's more GLA analysis of the Census here). 

The GLA map is better because (a) it uses ward boundaries, which unlike the statistical boundaries I used have not changed over time and therefore offer a like-for-like comparison; (b) it compares Census 2011 population to the 2001 mid-year population, which the GLA thinks is a more reliable figure than the 2001 Census figure, and (c) it's interactive! So I've put my map below the fold here, just for reference.

Thursday, 1 November 2012

The gender dimension of road danger

This BBC article about 'black box' devices in cars which monitor your driving for insurance purposes features lots of standard-issue outrage from drivers who can't see why how badly they drive should be anyone else's business but it also touches on the interesting issue of whether female drivers are safer than males. You don't have to look too hard to find plenty of commentary on this topic, but hard facts are more difficult to come by. Here's something from 2004:
Male motorists were responsible for 88% of all driving offences that resulted in findings of guilt in court in England and Wales in 2002, the Home Office statistics showed. Furthermore, men committed almost all the most serious offences, such as causing death and dangerous driving: women committed just 6% of the death or bodily harm offences in 2002 and just 3% of dangerous driving offences. Men were also responsible for 96% of vehicle thefts and 97% of offences relating to motorcycles.
Those are pretty huge differences, but perhaps, and I'm just speculating here, partly down to different treatment of men and women by the justice system. You can also look at the different rates at which men and women are involved in collisions resulting in injury, with the caveat that the figures don't necessarily imply anything about who's at fault. I looked at DfT's 2011 road casualties data, and found that in 85% of collision where a pedestrian died the driver of the vehicle (mostly cars but also vans, motorbikes, HGVs and a couple of bikes) was male, compared to 71% of cases resulting in serious pedestrian injury and 69% of cases resulting in slight injuries. This table suggests that men account for about 65% of the miles driven in Britain, so they do seem to have a higher rate of involvement in pedestrian casualties (trying to calculate rates for all kinds of collisions is more complicated).

What was most interesting to me is that males also account for a higher share of pedestrian casualties too: 68% of fatalities, 60% of fatal or serious injuries and 57% of slight injuries in 2011, according to this table. Other figures show that men and women do roughly equal amounts of walking, so these numbers do seem to provide some support for the idea that guys take more risks - or maybe just have worse judgement - than girls whether they're in cars or on foot.

The wider issue is that men also have more influence over transport policy and road safety, with the result that the issue is treated more as one of personal responsibility than as one of public health. The same cognitive biases that tell us we should be able to look out for ourselves ensure that we basically can't.