BMJ report bolsters 20 is plenty- 700 less casulaties in London

The BBC is carrying a report on 20mph zones in London.

"UK cities should have more 20mph speed zones, as they have cut road injuries by over 40% in London, a study claims.
In particular the number of children killed or seriously injured has been halved over the past 15 years, the British Medical Journal reported.


Main outcome measures All casualties from road collisions; those killed and seriously injured (KSI).
Results The introduction of 20 mph zones was associated with a 41.9% (95% confidence interval 36.0% to 47.8%) reduction in road casualties, after adjustment for underlying time trends. The percentage reduction was greatest in younger children and greater for the category of killed or seriously injured casualties than for minor injuries. There was no evidence of casualty migration to areas adjacent to 20 mph zones, where casualties also fell slightly by an average of 8.0% (4.4% to 11.5%).
Conclusions 20 mph zones are effective measures for reducing road injuries and deaths.


The London School of Hygiene and Tropical Medicine study estimates 20mph zones have the potential to prevent up to 700 casualties in London alone.
At 20mph, it is estimated only one in 40 pedestrians is killed in a crash.
This compares with a one in five chance for someone hit at 30mph"

"The greatest reduction was seen in children under the age of 11 years and in the numbers of all ages killed or seriously injured.
Cyclist injuries fell by 17% once 20mph zones came in, and injuries in pedestrians have been cut by almost a third.
There was also no evidence of a higher rate of casualties in areas bordering the 20mph zones, as in areas adjacent to 20mph zones casualties fell by an average of 8%. "


This is great evidence for 20 is plenty and counters some comments on the local press.
I've submitted a letter to the Herts Advertiser, let's have some more publicty from other people.