Doing 80 on a long, straight highway through the flatlands was once considered almost a part of the American birthright. But when the oil embargo pinched the U.S. in 1973, high-speed, gas-gulping joyrides looked like something the nation could ill afford. Congress forced the states to impose a 55-m.p.h. limit, and a tradition died. Though lower speeds have saved countless lives and millions of barrels of oil, many road runners hate slow-motion driving. I Can't Drive Fifty-Five, a popular song by Sammy Ha-gar, has become the anthem of speeding scofflaws.
Now, with prices at the pump dipping below 700 per gal.,...