The federal government really has no choice but to raise gas taxes within the next year or two. If not, the highway fund will reach a $5.7 billion deficit in 2010 and will be forced to cut obligations by 42 percent ($18.2 billion) from the 2009 obligation level.

The only question is how much the tax will be raised. The leading industry group AASHTO says a 3-cent increase is necessary to avoid a major cut and a 10-cent increase is required restore purchasing power to 1993 levels.

AASHTO also calls on state and local governments to increase transportation funding by $110 billion over the next eight years. They say increased tolls will be necessary on top of traditional funding sources.