Skip to Content
Streetsblog USA home
Streetsblog USA home
Log In
Cars

Fact-Checking the Toyota Hearing: Lower Speeds Increase Safety

Megan McArdle at the Atlantic, writing on today's Toyota hearing in the House oversight committee, hears Transportation Secretary Ray LaHood claim that "lowering the speed limit to 30 mph would not save any lives, which is why we have minimum speeds on highways."

lahood.jpgLaHood, at left, with the president at right. (Photo: whitehouse via Flickr)

Leaving aside the gaping logical hole in that statement -- which Robert Mackey of the New York Times suggests (check out the 12:04 post here) may have come from Souder's argument that lower speed limits would save more lives than "100% safe" cars -- there is plenty of research out there pointing to the beneficial effects of lower speeds on safety.

Traffic author Tom Vanderbilt recently cited the impact of 20 mile-per-hour urban speed zones on reducing road injuries in the United Kingdom, and a 2007 study by the AAA Foundation for Traffic Safety [PDF] outlined the following "general rule of thumb":

When travel speed increases by 1%, the injury crash rate increases by about 2%, the serious injury crash rate increases by about 3%, and the fatal crash rate increases by about 4%. The same relation holds in reverse: a 1% decrease in travel speed reduces injury crashes by about 2%, serious injury crashes by about 3%, and fatal crashes by about 4%.

Could LaHood be unaware of the relationship between lower speeds and decreased risk of injury? It's certainly possible -- despite the former GOP lawmaker's good record on infrastructure reform and sustainability, both in concept and in practice, he remains a relative newcomer to the nitty-gritty of transportation, as the Times reminded readers in a highly readable profile last year.

Stay in touch

Sign up for our free newsletter

More from Streetsblog USA

Streetsblog Joins Campaign for Public Financing of Non-Profit Media

New York provides tax credits to for-profit newsrooms. Now, non-profit digital outlets, public broadcasters and public access channels are seeking equal treatment. Doing so would strengthen our democracy.

December 26, 2025

Opinion: Why Urbanists Should Support Plant-Forward Policies 

Your plate is political, just like your choice to pedal instead of drive. And often, transportation and food politics have powerful intersections.

December 26, 2025

Thursday’s Headlines: Merry Christmas Edition

We're off today, and we wish you a very Merry Christmas!

December 25, 2025

Don’t Believe the Hype: NJ Turnpike Widening Still Happening

Gov. Murphy's late revision will just move the problem around, advocates say.

December 24, 2025

Opinion: Can AI Help Stop Car Crashes Before They Happen?

Proactive safety planning can save more lives than waiting until after crashes kill. But what's the proper role of technology in identifying future hot spots?

December 24, 2025

Wednesday’s Headlines Have a Clean Background

Uber isn't doing everything it can to keep violent felons out of the driver's seat, according to the New York Times.

December 24, 2025
See all posts