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

Friday’s Headlines Trust the Science

Who do you believe, 85 climate experts, or five people hand-picked by the Trump administration?

September 5, 2025

New York City Will Further Rein In Delivery Apps

A soon-to-pass bill would require safety equipment, plus a safety course.

September 5, 2025

Friday Video: How Public Transportation Fails ‘Fat’ People

Take a deep dive on the importance of size-inclusive transit, and what activists in Brussels are doing to get it.

September 5, 2025

Talking Headways Podcast: Wonders of the South Bay

VTA's Sam Sargent on the past, present and future of transit in the South Bay.

September 4, 2025

Thursday’s Headlines Lobby Congress

When the Biden administration's infrastructure act expires, it will pit cities versus states and roads versus transit.

September 4, 2025

Why More Communities Are Reconsidering Speed Limits From a Pedestrian’s Perspective

Is America's driver-centered approach to setting speed limits starting to shift? An engineer argues it is, and offers a reminder about why it matters.

September 4, 2025
See all posts