Lower Speed Limit Reduces Casualties in London
Introduction of 20 mph zones associated with 42 percent decrease in deaths and serious injuries
FRIDAY, Dec. 11 (HealthDay News) -- In London, the introduction of 20 mph speed zones has significantly reduced road injuries and deaths, according to a study published online Dec. 10 in BMJ.
Chris Grundy, of the London School of Hygiene and Tropical Medicine, and colleagues analyzed 1986 to 2006 police data on road casualties and estimated the effect of introducing 20 mph zones within 119,029 road zones with at least one casualty.
The researchers found that a lower speed limit was associated with a 41.9 percent decrease in road casualties, and that it had a greater effect on reducing deaths and serious injuries -- especially among young children -- than on reducing minor injuries. They also found that the lower speed limit did not cause increased casualties in adjacent areas, where there was an average decline of 8 percent in road casualties.
"The empirical evidence from Grundy and colleagues' study lends weight to the principles of speed management integrated within 'safe system' approaches to road safety designed to 'allow for human error without leading to death or serious injury,'" states the author of an accompanying editorial. "Common strategies for managing speed include setting and enforcing speed limits, 'engineering treatments' (such as road humps and roundabouts), and public education. A speed limit of 30 km an hour in built-up areas with a mix of vulnerable road users and motor vehicle traffic is considered a key attribute of a safe system."