Scripps Howard News Service:

High gas prices have convinced Americans to do what ceaseless carping by the greenhouse-gas scolds has failed to do ― drive less.

The number of miles Americans drove fell for the seventh consecutive month in May, the longest sustained slide since the late '70s and the first annual decline since 1980. Since November, Americans have driven 40.5 billion fewer miles than they normally had.

May is a bellwether month because the three-day Memorial Day weekend is the traditional start of the summer driving season, but even then driving was down 3.7 percent or 9.6 billion miles from the previous May. And curiously some of the biggest declines in driving were showing up in the north central states whose residents don't have much choice of transportation other than their cars.

Our collective national decision to drive less is showing up in increased mass transit ridership, weakening attendance at resort destinations, anemic car sales and an anticipated $3.1 billion shortfall in the federal highway trust fund, which is bankrolled by a tax on gasoline and diesel. However, that fund will not be allowed to languish. Congress loves it and recently voted by a large margin to give it an $8 billion infusion direct from the Treasury.

While foes of the internal combustion engine are pleased by the drop in miles driven, it has economic consequences that worry retailers. If Americans drive less, it could translate into spending less, and consumer spending determines the health of our economy.

Will this decline in driving signal a permanent change in American travel habits? Almost surely not. The century-old tradition of unfettered mobility is too ingrained to change significantly. When fuel prices stabilize or decline, Americans will do what they've always done since the Model T came along 100 years ago this October ― get in the car and drive somewhere.