The U-S Chamber of Commerce is suggesting the federal government tax hybrids and other fuel-efficient cars.
The chamber says the federal Highway Trust Fund is running out of money to maintain the nation's highways, and that Congress needs to consider new sources of revenue.
Chamber leaders also are suggesting billing drivers for miles driven.
The study also recommends the federal gas tax of about 18 cents a gallon be indexed for inflation.
Why tax hybrids and other alternative fuel vehicles? Proponents say drivers should have to pay their fair share to fill potholes and fix bridges, regardless of how much or what kind of fuel they use.