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Increased Speed Limits Cost 33,000 Lives in U.S.

Increased speed limits across the U.S. over the last two decades have cost at least 33,000 lives, according to a study by the Insurance Institute for Highway Safety (IIHS). In 2013 alone, the increases led to an estimated 1,900 additional deaths, essentially cancelling out the improvements in vehicular fatalities due to frontal airbags.

In the 1970s and 1980s, a majority of states set their top state speed limits at 55 miles per hour (55 mph) due to a 1973 federal measure known as the National Maximum Speed Limit. Passed by Congress due to concerns over fuel availability, the measure mandated that states set 55 mph as their maximum speed limit in order to receive their full share of highway funding.

The law was relaxed in 1987, when Congress allowed states to raise their speed limits to 65 mph on rural interstates, and then completely repealed in 1995. Since 1995, travel speeds have increased across the U.S. IIHS researchers found fatalities also went up, both with the partial repeal of the National Maximum Speed limit in 1973, and again when the measure was fully repealed in 1987.

As of January 2013, only Washington D.C. had maintained a 55 mph maximum speed limit. Fourteen states have a maximum speed limit of 75 mph, while nineteen others—including California—have a maximum speed limit of 70 mph.

Charles Farmer, IIHS vice president for research and statistical services, said 33,000 fatalities is likely an underestimate, because the analysis only considered increases in the maximum speed limit. Often, the maximum speed limit only applies to rural interstates. Many states also increased speed limits on urban interstates.