GREEN BAY, Wis. — Seeking to reduce the nation's dependency on foreign oil after the shock of the Arab oil embargo of 1973-74, Congress moved swiftly to establish the first fuel economy standards for motor vehicles.

Enacted in 1975, the Corporate Average Fuel Economy rules mandated that each automakers' fleet of passenger cars had to average 18 miles per gallon by 1978 and 27.5 by 1985. Light trucks — a category that later included SUVs and minivans — were allowed to meet lower targets.

Congress designed CAFE to reverse a trend toward declining gas mileage and it was remarkably effective in doing so during its early years. Unfortunately, its standards have improved only slightly since 1985. In fact, today's mileage for new cars and trucks is at the lowest level in 20 years — with harmful consequences for national security, the economy, and the environment.

The new 110th Congress needs to get serious about strengthening CAFE since the technology now exists to build more fuel-efficient vehicles without much sacrifice in size, performance or safety — as long as the new stand-ards are phased in gradually.

That was the conclusion of a major study by the National Academy of Sciences as far back as 2002. New hybrid technologies and other breakthroughs make that goal even more realistic today.

Raising the CAFE standards will be a more effective, efficient and faster route to weaning the nation from its gas-guzzling habits than relying on automakers voluntarily to build new fuel-sipping vehicles or pushing the production of corn-based ethanol.

And tightening the rules for CAFE also is more politically realistic than trying to increase federal gasoline taxes, a policy alternative many analysts recommend.

Consider these facts. Sixty percent of the oil consumed in the United States last year was imported — far higher than the rate during the 1970s and 1980s. Our increased addiction to foreign oil obviously creates significant risks to national and economic security.

America currently uses more than 20 million barrels of oil a day. About 70 percent of that goes to transportation, with most of it pumped into the fuel tanks of our cars, SUVs and light trucks.

With an emerging scientific, economic and political consensus prodding the nation to quickly cut greenhouse gas emissions, improving fuel economy is a good place to start since motor vehicles now account for about one-third of our carbon releases.

Improving gas mileage also will put more inexpensive, fuel-efficient vehicles into dealer showrooms and make driving more affordable for millions of American motorists as gas prices continue to soar in the years ahead.

While President Bush has acknowledged that the nation is addicted to oil, he proposed no initiatives that could end the addiction although earlier this year he did endorse a modest increase in fuel economy standards and advocated greater use of renewable fuels such as corn-based ethanol.

Congress can do better on both fronts and apparently intends to. Prominent lawmakers from both parties are calling for annual increases in CAFE standards of 4 percent — or at least one mile per gallon — over the next 10 years, setting different efficiency targets for vehicles of varying size and weight.

While these goals are technically feasible and economically realistic, Congress needs to address the concerns of struggling Big Three domestic auto- makers, who worry that stringent requirements could further depress sales and force additional layoffs.

It is hoped they will roll up their sleeves and get on with the task. Setting tough CAFE standards is the single most important action the nation can take to reverse its dependency on oil. The new Congress must find an economically acceptable and politically feasible way to do that.

Michael Kraft is professor of political science and public policy at the University of Wisconsin-Green Bay, and author of "Environmental Policy and Politics."