By mandating that automakers build cars capable of traveling 35 miles per gallon by 2020 and that 36 billion gallons of the United States’ transportation fuel come from renewable sources by 2022, the Energy Independence and Security Act of 2007 was intended to reduce the country’s dependence on imported petroleum.

The recession “may buy us a couple more years,” but rising fuel demand will soon wipe out any reductions arising from the legislation, says Kenneth Berlin, the author of several reports on energy security and global warming published by the Center for American Progress, a Washington-based think tank.

In an attempt to further reduce oil imports–and greenhouse-gas emissions–the Obama administration pledged $2.4 billion of stimulus funds last March to manufacturers of components for plug-in hybrids and those seeking to build charging stations and other infrastructure for electric vehicles.

Stimulus funds are intended to be a one-shoot boost. In the longer term, energy legislation currently before the U.S. Congress could spur the development of new transportation technologies, particularly electric vehicles. The House has already passed a bill mandating that electric utilities develop plans to support the use of plug-in hybrids (ideally, such plans would include public charging stations). The bill also offers financial supports to offset the higher cost of electric vehicles. The Senate version introduced in September similarly demands work on plug-in hybrids and charging stations, but it does not contain a specific provision for purchase offsets.