The Virginia Department of Transportation’s revenues are expected to be more than $1 billion less than anticipated over the next six years, according to transportation officials.

The sputtering economy, which has eaten into nearly every aspect of state government, is expected to cut deeply into VDOT’s program to maintain and expand its road network. The Commonwealth Transportation Board heard estimates this week that six-year revenues are $1.1 billion below estimates from a year ago, according to reports.

Proponents of increased transportation funding in Virginia seized on the news to further arguments for a gas tax increase. The state Senate wants to add 5 cents to the 17.5 cent fuel tax to pay for a growing highway maintenance deficit, which was made worse by the abolition of the “abuser fees” on bad or dangerous drivers.

The historically anti-tax House of Delegates, however, is almost certain to block the measure, which could raise $250 million a year.

“And of course revenues are declining at the same time construction costs are increasing,” the Northern Virginia Transportation Alliance said Thursday. “Still think there’s no reason to even think about raising the gas tax?