CARS.COM — This year marks four decades since President Richard M. Nixon signed into law a mandate that set the maximum national speed limit at 55 mph, helping to fend off an oil crisis, diminishing Americans' ability to make good time on a cross-country road trip and inspiring rocker Sammy Hagar's signature song. It's been nearly two decades since that law's repeal and, since then, two-thirds of U.S. states have picked up the pace significantly, raising their speed limits to 70 mph or higher on stretches of their roadways.
Related: Texas Opens High-Speed Toll Road
So which state is the fastest? Put another way, which state's roads and highways have the highest average top speed limit?
Well, if you're familiar with the saying, "everything's bigger in Texas," the sentiment extends to speed limits, too. The Lone Star State not only lays claim to the fastest posted limit on a single highway in the U.S., it also boasts the greatest overall top speed when you average the highest speed limits on its rural interstates, urban interstates and other limited access roads, as compiled by the Governors Highway Safety Association.
That nonprofit group, which represents the nation's state and territorial highway safety offices, lists the 85-mph speed limit on Texas' roads as the highest in speed limit the U.S. Moreover, the state's average top speed limit for all three types of roadways is 78.3 mph. That's nearly 2 mph greater than the average speed limit in the next-fastest state, Idaho, where roads have a top speed limit of 80 mph and an average top speed of 76.7 mph.
On the other end of the speed limit spectrum are Alaska and the District of Columbia, both of which have a top speed and average top speed for vehicles of 55 mph, according to the GHSA.
As Cars.com previously reported, the high-speed portion of Texas State Highway 130, which stretches 91 miles of road between San Antonio and Austin, became the nation's first 85-mph toll road in late 2012. Also, as of late July, Idaho raised speed limits for vehicles to 80 mph on stretches of several interstate roadways. The Gem State's transportation department initially put the brakes on the speed hike, following lawmakers' authorization of the increase, so that it could complete traffic safety studies at the urging of the AAA of Idaho. Those driving studies, according to Idaho's KTVB-TV news, have been completed, and crews began replacing speed-limit road signs on July 24.
Driving safety advocates generally don't view raising speed limits in a favorable light. At the time Texas debuted its 85 mph speed limit, Insurance Institute for Highway Safety spokesman Russ Rader said in a statement that, "the research is clear that when speed limits go up, fatalities go up." That said, the 55-mph national limit wasn't set for safety's sake, but rather in an effort to conserve fuel on a national level during the 1973 oil crisis, when gas prices quadrupled.
Since that time, we as a nation of drivers have hit the gas across the map. Four states — Idaho, Texas, Utah and Wyoming — now have top authorized limits for vehicles of at least 80 mph. A dozen more states have top speed limits of 75 mph, including Kansas, Louisiana, Maine, Montana, Nevada, New Mexico, North Dakota, Oklahoma and South Dakota. Moreover, 22 additional states have a maximum speed limit for vehicles of 70 mph, five of which (Michigan, Mississippi, North Carolina, Pennsylvania and Tennessee) average 70 mph across their urban and rural interstates and other limited-access roads, as listed by the GHSA.
In addition to the aforementioned pokiest places of Alaska and the District of Columbia and their 55-mph limits for drivers, five more states — Delaware, Hawaii, New York, Rhode Island and Vermont — all have top speeds for drivers of no more than 65 mph and average top speeds in just the high-50s.
See how your state's roads rank nationally in the chart below.
Editor's note: This post was updated on Aug. 18 to change a reference to Texas to its correct nickname, the Lone Star State.
Cars.com illustration by Paul Dolan
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