After a long wait--more than 20 years--significant new fuel-economy standards look as though they'll finally be signed into law. The Senate has passed a bill, which President Bush has indicated that he'll sign, that would raise the standards to 35 miles per gallon by 2020. But while this is a welcome development, it could take decades before the changes make much of an impact on fuel consumption and prices. Indeed, by that time, we'll likely be burning more gas than we do today, even with the new fuel standards, because more people will be driving. Near-term changes will require measures that encourage consumers to use less gas.

One option is to mandate the use of biofuels--something that's included in the current bill--which could offset gasoline consumption with ethanol. But increased use of ethanol could have unintended consequences, including damage to the environment and increased food prices. And until new technology is developed for converting biomass into ethanol, the fuel will only replace a small fraction of the gasoline used in the United States. What's more, it could be just as expensive as, or more expensive than, gas, since rising demand for corn to make ethanol drives up prices.

A better way to cut gasoline consumption in the near term could be the use of incentives to get people to drive less. John Heywood, a professor of mechanical engineering at MIT, who studies transportation issues, suggests that a combination of cameras for monitoring speed violations and education programs to encourage driving styles that use less gasoline could make a significant impact. Heywood is planning to study just how much people could save by easing up on the gas pedal. He also suggests that a system of fees added to the purchase price of gas guzzlers and rebates for efficient vehicles could help drive down fuel consumption.