Skip to Content
Streetsblog USA home
Streetsblog USA home
Log In

What if you could reliably pinpoint the street segments all over the country where speeding traffic poses a constant threat to life and limb? That could be a very powerful tool to identify and redesign dangerous streets.

At a time when traffic fatalities are rising rapidly and the National Transportation Safety Board acknowledges that excessive vehicle speeds contribute to America's sky-high traffic death rate, the time is ripe for that kind of analysis.

Two transportation researchers say a national map of dangerous traffic speeds could be possible. Eric Sundquist and Michael Brenneis at the State Smart Transportation Initiative report that U.S. DOT has purchased a vast set of traffic speed data collected by the firm INRIX, which it will share with state DOTs.

The feds aren't thinking about analyzing speed as a safety problem, however. "The US DOT is buying the data from INRIX so that DOTs can comply with performance measure requirements around delay and reliability," Sundquist and Brenneis write. In other words, U.S. DOT is thinking about congestion and traffic delay.

But with the data now in the hands of state DOTs, Sundquist and Brenneis say there's no reason it can't be used to save lives:

One application we haven’t seen -- and we’d like to hear from anyone doing it or interested in doing so -- is for speed management.

The notion is simple: The data provide average speeds by time and place, which can pinpoint congestion and reliability issues. They also indicate areas with excessive traffic speed. And while federal performance measures focus on the former, it’s possible to imagine speed management measures as well.

And in fact some exist. This is a measure established by the city of Los Angeles: “Ensure that 80% of street segments do not exceed targeted operating speeds by 2035.”

The data isn't as fine-grained as detailed speed studies, which capture the distribution of driver speeds, not just the average. But Sundquist and Brenneis believe that average speed can still be a useful metric to identify dangerous conditions. They're asking researchers who want to refine these ideas to contact them.

More recommended reading today: Plan Philly reports on SEPTA's plans to improve service and increase ridership by redesigning its network of 126 bus routes. And Better Burque shares photos of "Suddenly Ending Bike Lanes" around Albuquerque.

Stay in touch

Sign up for our free newsletter

More from Streetsblog USA

Friday Video: How ‘Car Brain’ Warps the Way We See the World

How can we fix the brains distorted by car culture?

January 16, 2026

Friday’s Headlines Are the Best

People for Bikes named its top bike lane projects of the past year.

January 16, 2026

Talking Headways Podcast: The Lost Subways of North America

Author Jake Berman discusses transit histories through the lens of racial dynamics, monopolies, ballot measures and overlooked cities.

January 15, 2026

A ‘Demographic Time Bomb’ Is About To Go Off — And the Transportation Sector Isn’t Ready

A top firm is warning that the "silver tsunami" will have big implications for the climate, unless U.S. communities act fast.

January 15, 2026

Thursday’s Headlines Shoot for the Moon

What if the U.S. spent anything near what it spends on highways on transit instead?

January 15, 2026
See all posts