The original 55 mph speed limit was initiated in response to the energy crisis in the mid 1970s.
However, the move was unpopular then and it would probably be unpopular now.
"Every five miles over the speed limit of 60, you use 10% more gas," Anita Flippin, /*AAA Carolinas*/, said.
Slowing down to save gas was the law across the nation 34 years ago. Speed limits historically had been left to the states, but in 1974 congress adopted a 55 mph rule to help the nation save /*gas*/.
"It's was a little slower, but it wasn't a major inconvenience," Cary resident Ken Lloyd said. "You just planned your trip a little longer."
Some drivers have already slowed down regardless of the legal speed.
"At home I have an SUV and I'm doing 55, and I don't care what anyone else says," Pennsylvania resident Eddie Jones said.
But on I-40, slowing to 55 is a lonely choice.
When Eyewitness News hit the road and drove 55 in the slow lane, everyone passed the vehicle. The speed limit is 65.
And some wonder if one driver slowing to 55 compromises safety as they try to save fuel.
"I'm no expert," motorist Lloyd said. "But they say that people who actually drive slower than the posted speed limit cause as many if not more accidents as people who are cheating a little bit."
The DOT says modern interstates are designed for non-congested speeds of 65 to 75 mph.
Currently there is no serious talk of lowering the speed limits, but when congress adopted the 55 mph law in 1974, gasoline was 40 percent cheaper even when you adjust for inflation.