Car driving at speed on the highway

Nearly 37,000 additional people have died in traffic incidents over the last quarter of a century because of rising speed limits on our nation’s roadways, according to a new study from an insurance-industry-funded group.

The researchers from the Insurance Institute for Highway Safety found that for every 5 mph increase in a highway’s speed limit, roadway fatalities rose 8.5 percent.

Although road deaths are lower overall than they were in 1993, they’re still higher, the study concludes, than they would have been had speed limits remained the same.

CR has analyzed the causes of persistent traffic deaths and the reasons behind stubbornly high annual totals despite the advent of advanced vehicle safety systems, such as automatic emergency braking. Speed remains a significant reason, CR found.

“While the statistics for speed alone are scary, it’s expected that they could have been much worse if cars hadn’t made so many gains in terms of performance and overall safety,” says Jennifer Stockburger, director of operations at CR’s Auto Test Center.

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Since the nationwide 55-mph speed limit was abolished in 1995, 41 states have increased their speed limits to at least 70 mph on highways. Seven states have adopted an 80-mph speed limit on some highways, and one stretch of Texas tollway has a speed limit of 85 mph. Six states have increased their speed limits since 2013.

There are about 5,000 more roadway deaths annually in recent years since a historical low point in 2011. In addition to speeding, other major contributing factors to the rise in deaths include drunken driving and not wearing a seat belt. There also has been a rise in pedestrian and cyclist fatalities.

The IIHS study examined annual traffic fatality data from 1993 through 2017, controlling for factors including the percentage of young drivers on the road, seat belt use, and unemployment. (The IIHS is partially funded by insurance companies.) The study found that an additional 36,760 people were killed on roadways during those years than would’ve been expected if speed limits hadn’t gone up. That’s roughly equivalent to the total number of people killed in all car crashes in the U.S. in each of the past few years.

If U.S. speed limits had been kept at 1993 levels, about 1,900 lives would have been saved in 2017 alone, the IIHS says.

Critics of lower speed limits argue that the time drivers save by going faster is crucial, but study author Charles Farmer says any gains there aren’t worth the risk.

“Driving 70 instead of 65 saves a driver at best 6 and a half minutes on a 100-mile trip,” he says. “Before raising speed limits, state lawmakers should consider whether that potential time savings is worth the additional risk to lives.”