Thursday, June 30, 2005

Getting the speed hump

As part of their campaign to open up Birmingham to allow car drivers free rein - we've already seen them get rid of bus lanes that get in the way of driving into the City from Sutton Coldfield - the Tory/Liberal Democrat council had a go at speed bumps last week. The plan is to create a network of 'Blue Routes' across the city that will be kept clear of traffic calming - even if it means removing exisiting measures - to allow emergency vehicles to get through faster.

I'm a little puzzled why this should be news - local authorities have always had a statutory duty to consult with the emergency services before traffic-calming measures are put into place and this has been done. It has to be noted that the services concerned haven't always responded to such consultation, so perhaps they should take a little more responsibility themselves.

This kicked off a couple of years ago, when the head of the London ambulance service reckoned that cutting response times by one minute could save 500 lives a year from cardiac arrest. At the request of the GLA, the London Health Observatory took a glance at this theory and how it relates to traffic calming overall. Their conclusion was that traffic calming is only likely to delay emergency response in a tiny number of cases - a delay of a minute would require them to cover around a mile of traffic calming at 20mph and there are far greater delays caused by patients waiting to call for help.

The benefits of traffic-calming more than outweighed any likely risk - if a pedestrian is hit by a car travelling at 20mph, 95% will survive. Increase the speed to 30mph and the survival rate drops to 50%. Impacts at 42mph will only leave 5% of victims alive. Aside from that, traffic calming makes walking more attractive, which has its own health benefits. Traffic calming works, it is popular with local residents and pays for itself rapidly - within a year in most cases.

If you really want to improve response times, the answer isn't to rip up speed bumps, but to reduce congestion, so encouraging car usage isn't really the right answer. It does pander to the prejudices of voters, though, so that's all right.

1 comment:

Bob Piper said...

I can't be totally sure of this, but I am sure comrade Len Gregory, Birmingham Traffic Czar once told me that his son is an ambulance driver.... although I am sure this is entirely unconnected.