Speed humps cost lives

Paramedics are warning that speed humps on London streets are killing hundreds of people a year by increasing ambulance response times. Sigurd Reinton, chairman of the London Ambulance Service, claimed in February that more lives are being lost through delays caused by speed humps and other calming measures than are saved by them.

“The situation is about more than road humps—our ambulances also have to slow down for chicanes and width barriers, often to walking pace”, he said. “The fact that side streets have been shut off also has an impact as we then get caught up in the increased traffic on other routes.

“There is no doubt that the policies are well-intentioned, but I feel that the introduction of congestion charging offers an ideal opportunity to review their effectiveness”.

Research in Boulder, Colorado, supports Reinton’s claims. It suggests that for every life saved by traffic calming as many as 85 people may die because emergency vehicles are being held up. The report found response times are typically extended by 14% by speed reduction measures.

Cardiac arrests were of particular concern in the study: 90% of victims survive if treated within two minutes, though the rate falls to just 10% if they go untreated for six minutes. London has particularly low survival rates: among the 8000 people who suffer arrests each year only 2% of the most serious cases are revived.

The ambulance service calculates that each of the capital’s 20 000–30 000 humps can add 15 seconds to a journey, with each minute’s delay responsible for a 10% reduction in survival rates for cardiac arrest patients. Reinton says even the strictest traffic calming could reduce London road deaths by only another 100 a year, while his crews could save up to 800 more lives annually if calming measures did not delay them.

Emergency services chiefs have also previously criticised councils for introducing speed humps without any apparent consideration of their adverse effects. Although there are no signs of London ambulance crews claiming injuries as a result of speed humps, two firefighters in Sacramento, California, suffered spinal injuries in separate incidents when they hit their heads on the cab roof as their vehicle went over a hump. One was forced to take early retirement, the other was permanently disabled.

Humps have come in for criticism for other reasons, too. Although the official Department for Transport line is that they can increase car emissions by between 1% and 60%, Austrian researchers found exhaust pollution can soar 10-fold as drivers accelerate away from humps.

Transport for London (TfL) said it understood Reinton’s concerns but did everything it could to strike the correct balance. “We give great consideration to balancing the needs of road users and pedestrians”, said Derek Turner, managing director of street management for TfL. “Traffic calming measures should only be installed where it is necessary to reduce casualties” (based on a report in The Times (London), February 2003; submitted by Barry Pless).