20mph Zones Saving Lives in London

Over the last decade, London has established more than four hundred 20 mph zones across the city. The 10mph decrease has had a significant effect on the number of fatalities.

1 minute read

March 23, 2010, 12:00 PM PDT

By Tim Halbur


Noah Kazis writes, "The safety effects of the 20 mph zones have been enormous for pedestrians, cyclists, and drivers alike. In London, serious traffic injuries and fatalities have fallen by 46 percent within the zones, according to the prestigious British Medical Journal. Deaths and serious injuries sustained by children have dropped 50 percent. There's even a small spillover effect, with areas immediately adjacent to 20 mph zones seeing an eight percent reduction in total injuries and deaths. The science is so clear that in 2004 the World Health Organization endorsed 20 mph speeds as an essential strategy to save lives."

Thanks to Noah Kazis

Monday, March 22, 2010 in Streetsblog

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

July 2, 2025 - Diana Ionescu

White and purple sign for Slow Street in San Francisco, California with people crossing crosswalk.

San Francisco Suspends Traffic Calming Amidst Record Deaths

Citing “a challenging fiscal landscape,” the city will cease the program on the heels of 42 traffic deaths, including 24 pedestrians.

July 1, 2025 - KQED

Google street view image of strip mall in suburban Duncanville, Texas.

Adaptive Reuse Will Create Housing in a Suburban Texas Strip Mall

A developer is reimagining a strip mall property as a mixed-use complex with housing and retail.

2 hours ago - Parking Reform Network

Blue tarps covering tents set up by unhoused people along chain link fence on concrete sidewalk.

Study: Anti-Homelessness Laws Don’t Work

Research shows that punitive measures that criminalized unhoused people don’t help reduce homelessness.

4 hours ago - Next City

Aerial tram moving along cable in hilly area in Medellin, Colombia.

In U.S., Urban Gondolas Face Uphill Battle

Cities in Latin America and Europe have embraced aerial transitways — AKA gondolas — as sustainable, convenient urban transport, especially in tricky geographies. American cities have yet to catch up.

6 hours ago - InTransition Magazine