Northern Virginia's Interstate 66, a notorious stop-and-go rush-hour nightmare, may get express lanes like those now helping ease traffic on the Beltway.

"We have horrible congestion," said Fairfax County Supervisor Pat Herrity, R-Springfield. "We need a solution today; we can't afford to wait years for [a new Metrorail extension]. The express lanes are the ideal solution."

And Herrity has the support of the state's top transportation official.

"Obviously, no decision has been made. However, it would be rational to extend the express lanes network down 66 to provide [high-occupancy vehicle] and transit options," said Virginia Secretary of Transportation Sean Connaughton.

The new lanes would stretch 25 miles from the Beltway to Gainesville and would operate much like the Beltway's express system, with buses and carpoolers allowed on for free and other drivers paying a toll using E-ZPasses. A private company could build, finance and manage the lanes, raising tolls during peak periods to keep them traffic-free, Herrity said.

State planners last month released a study that found travel times on Interstate 66 unpredictable. Most of the traffic during morning and evening rush hours typically travels at no more than 30 mph.

The study also found it would take 18 miles of extra highway lanes to keep traffic flowing freely through 2040, without other solutions such as express lanes or train service.

The Commonwealth Transportation Board will decide later this year on whether to study express lanes, trains, buses or extra regular lanes for the highway.

If Virginia officials approve the construction of express lanes, Herrity said, they will have to tackle a number of issues, including how to purchase land to expand the highway. And he said there's no way the express lanes could start at the Potomac River, in Arlington County, which sued in 2009 to block the Interstate 95 express lanes.

"If you go inside the Beltway, we'll be in lawsuits with Arlington for decades," Herrity said. "We can't afford to wait."