We’re all probably of two minds about speed limits, chafing under their confines (and enduring the occasional ticket from cops with quotas) but also recognizing that they’re saving lives.

Cars.com recently pointed out that since the mandatory 55 mph speed limit was repealed in 1995, more than two thirds of the states have gone up to at least 70 mph, and libertarian-minded Texas is at 85 mph. Much of the Midwest and West (but not the West Coast) is at 80 mph.

Alaska is a colder version of Texas, but for some reason it hasn’t gone to crazy speed limits, and Connecticut, Delaware, New York, Massachusetts, Vermont and Rhode Island (plus the District of Columbia) are all at 65 mph or below.

Look at the map above; the speed limits appear in broad swatches across the country, like regional preferences. New England (minus Maine and New Hampshire) are the lands of steady habits, and the speed demons are west of the Mississippi.

Raising speed limits tends to be popular politically, but it’s not really a good idea. In addition to wasting a lot of gas (because speeding cars are inefficient) it’s dangerous. And that’s not just me saying that.

Do these

Do these "you're speeding" signs slow people down? (Photo: Jim Motavalli)

Cars are safer today than they ever were, which is why road fatalities overall in the U.S. haven’t gone up (despite a larger population leading to many more miles traveled). But that doesn’t mean fatal crashes haven’t gone up in the states that raised their limits. A new study from the University of Illinois at Chicago School of Public Health is rather alarming in that regard. 

“The primary finding of our study was that over the 10-year period following the repeal of National Maximum Speed Law [1995 to 2005], there were approximately 12,500 deaths due to the increased speed limits across the U.S.,” said Lee Friedman, assistant research professor of environmental and occupational health sciences at UIC.

The study said that deaths went up 3.2 percent because of higher limits on all types of American roads. The biggest increase — 9.1 percent — was on rural interstates (compared to 4 percent on urban interstates).

And, despite what Sammy “I Can’t Drive 55” Hagar might say, the national speed limit saved lives. “There was a drop of almost 17 percent in fatalities in the first year after the speed laws were reduced to 55,” Friedman said.

Some may think that speed limits are an infringement on individual liberties, and libertarians seem to hate them. I note with interest that some libertarian sites claim that killing mandatory 55 speed limits saved lives. “Studies showed that letting people drive as fast as they wanted to actually reduced highway fatalities,” claimed Logicallibertarian.com in 2011.

This grandiose claim is based on evidence from just one state. A group I’ve never heard of called the National Motorists Association produced a study that claims “the safest period on Montana’s interstate highways was when there were no daytime speed limits or enforceable speed laws.” There may be many reasons for that phenomenon, and it’s not convincing proof. Evidence that speed limits reduce mayhem on the roads is much stronger.

“Lower speeds save lives,” reports The Gothamist. “The science is clear: If a pedestrian is hit by a speeding driver traveling at New York City's default speed limit of 30 mph, there is a 30 percent chance that person will die. That number goes up to 80 percent if the driver is going 40 mph, as too many motorists do. But at 20 mph — the speed limit we should have — there's a 98 percent chance that same pedestrian will live.”

There were 156 pedestrian deaths on New York’s roads in 2013, up from 142 in 2011. That's far too many. Lower speed limits, safer roads: it's a simple equation that mostly holds true.

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Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.