In a survey of the first 200 20mph zones around Britain, researchers at the Transport Research Laboratory found the number of accidents involving child pedestrians fell by 70 per cent and those involving child cyclists by a half.
Local authorities were first given the right in December 1990 to apply to the Department of Transport permission to impose 20mph limit zones and there are now nearly 300.
The councils must implement traffic-calming measures before imposing the speed limit and most zones have been installed in residential areas, though a few are in town centres. Previous research has shown that while at 30mph nearly half of children hit by a car will die, at 20mph one in 20 will be killed.
The researchers found that overall speeds fell by just over 9mph in the new zones, showing that most motorists obeyed the limits, and that there was a 6 per cent drop in accidents for every 1mph reduction in speed. The research also suggests that while traffic increased on nearby roads as people sought to avoid the 20mph zones, the accident rate did not.Reuse content