Organisation: London School of Hygiene and Tropical Medicine
Date uploaded: 22nd September 2010
Date published/launched: February 2009
The aim of thsi report is to quantify the effect of the introduction of 20 mph traffic speed zones on road collisions, injuries, and fatalities in London.
Analyses were made of longitudinal changes in counts of road injuries within each of 119 029 road segments with at least one casualty with conditional fixed effects.
Estimates of the effect of introducing 20 mph zones on casualties within those zones and in adjacent areas were adjusted for the underlying downward trend in traffic casualties.
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%).
The report concludes that 20 mph zones are effective measures for reducing road injuries and deaths.
For more information contact:
Chris Grundy