Do Speed Bumps Increase Traffic Safety?

Randall O'Toole and Kathleen Calongne examine the findings from a recent report that suggests that speed humps make streets 50 to 60 percent safer for children, and reach a different conclusion.

1 minute read

August 15, 2006, 5:00 AM PDT

By Chris Steins @planetizen


"A recent paper purporting to show that speed humps make residential streets safer for children actually shows nothing of the kind. In fact, the study's data can even be interpreted to mean that humps make streets more dangerous.

The study used a database showing when and where 1,600 speed humps were installed on Oakland streets between 1995 and 2000. Ideally, the researchers would have compared accident rates on those streets before the speed humps were installed with rates after -- but they did not. Or they could have compared accident rates on those streets with rates on streets that did not have speed humps -- but they did not, at least not directly.

...Curiously, the researchers found that having a speed hump in front of your home reduces your child's chances of being hit by a car a quarter mile away from your home by the same percentage as they reduce the chances of being hit in front of your home. The study does not say how a speed hump in front of your home protects your children when they are a quarter mile away. This strange finding should have signaled to the authors that something was wrong with their methods."

Thanks to Randall O'Toole

Saturday, August 12, 2006 in The Thoreau Institute

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 9, 2025 - Diana Ionescu

Green vintage Chicago streetcar from the 1940s parked at the Illinois Railroad Museum in 1988.

Chicago’s Ghost Rails

Just beneath the surface of the modern city lie the remnants of its expansive early 20th-century streetcar system.

July 13, 2025 - WTTV

Bend, Oregon

Bend, Oregon Zoning Reforms Prioritize Small-Scale Housing

The city altered its zoning code to allow multi-family housing and eliminated parking mandates citywide.

5 hours ago - Strong Towns

Blue and silver Amtrak train with vibrant green and yellow foliage in background.

Amtrak Cutting Jobs, Funding to High-Speed Rail

The agency plans to cut 10 percent of its workforce and has confirmed it will not fund new high-speed rail projects.

6 hours ago - Smart Cities Dive

Green Skid Row mural satirizing city limit sign in downtown Los Angeles, California.

LA Denies Basic Services to Unhoused Residents

The city has repeatedly failed to respond to requests for trash pickup at encampment sites, and eliminated a program that provided mobile showers and toilets.

7 hours ago - Los Angeles Public Press