20mph zones across London are saving lives

New research on 20 MPH zones in London proves that they significantly reduce road casualties.

The study done by the Department of Public Health and Policy at the London School of Hygiene and Tropical Medicine examined police records of accidents from 1986 to 2006 and compared the rate of accidents in areas that changed from 30mph to 20mph. The conclusion was that the lower speed limit reduced the casualties by 41.9%.

The study also established that the rate of casualties did not increase in the roads around the 20mph zones showing that the zones did not simply push the problem into other areas.

Each year there are around 3000 deaths on the roads in England and Wales and a further 27,000 serious injuries from road accidents. That is enough people to fill the proposed Bristol City Stadium, every year. It is estimated that nationally one person in every hundred has been bereaved by a road accident.

Excessive speed is cited as a contributing factor in 26% of all road accidents. Around 60% of road fatalities occur on rural roads where the national speed limit of 60mph applies. But the pedestrian and cyclist deaths occur mainly in urban areas. The people most likely to be walking are those from lower incomes, the elderly and children.

The number of deaths and injuries from road accidents has been steadily declining in this country, but this may in part be due to the reduced number of people who actually walk or cycle compared to those who use cars.

When a car hits a pedestrian at 30mph there is a one in five chance that the pedestrian will be killed. If the car is travelling at 20mph then there is a one in 40 chance of a fatality. That is, a pedestrian is eight times more likely to survive a collision at 20mph than at 30mph.

The report estimates that the 20mph zones in London save 200 lives a year. Anyone who follows the news in Bristol will be aware that there have been a number of high profile hit and run accidents recently as well as frequent accidents involving pedestrians or cyclists. So lower speeds would save lives here too.

And 20mph zones have many other benefits including

• Greater modal shift to walking and cycling
• Increased child mobility
• Lower noise and pollution levels
• Greater independence for the elderly and infirm
• Calmer driving conditions with easier side road integration
• Increased amenity in urban centres.
• A greater sense of community wellbeing.
• Increased health through increased walking and cycling.
• Less traffic.

Bristol City Council proposed the introduction of 20mph zones in Inner East and Inner South Bristol in January 2009 as part of the Cycling City initiative and has conducted consultations during the year. The results show that most people not only support the current plans but that many wanted the zones extended even further. Less than 2% of the people consulted objected to the zones.

Related links:

British Medical Journal
Bristol City Council
20 Is Plenty Campaign