Imagine the line that would appear at a gas station if it started selling gas 29 cents below the prices of its competitors. Then imagine how long the line that would be if the discount were 94 cents. Motorists could realize such dramatic savings, the U.S. Department of Energy claims, by simply cutting their highway speeds to 60 mph. Unfortunately, even with gas selling at over $4 per gallon, they won’t do it; and few politicians have been willing to stick their necks out and say the obvious: that government should reduce the national speed limit, the way it did when there were gas shortages and skyrocketing prices in the 1970s, and enforce it.

Sen. John Warner is the glaring exception, which is both telling and sad. He’s retiring at the end of this year, and so has nothing to lose politically. No one else has had the guts to embrace his call for a move that would cut consumption between 7 percent and 23 percent, and reduce oil imports by nearly a billion barrels per year. Why not?

Well, Americans regarded President Nixon with contempt when he imposed the double-nickel speed limit back in 1974. A good many of them ignored the lower speed limit, and continued to ignore it until it was repealed two decades later — when the world was awash in cheap oil. But not everyone was scornful, so it did reduce consumption and imports, and saved lives. Perhaps if it hadn’t been raised back up, to 65, 70, even 75 mph in some states, we wouldn’t be paying $4-plus for gas today.

Warner has asked the energy department to analyze the issue and come back with a recommendation for an optimum speed limit. At that point, he says he’ll try to get Congress to pass a law supporting the lower limit. For what it’s worth, a trade group representing 3.5 million truck drivers and 37,000 trucking companies supports such a measure — a drop to 65 mph. That wouldn’t be bad — reducing consumption at 75 mph by 27 percent — but with the economy so clearly in the doldrums because of current gas prices, 60 mph would make even more sense.