Virginia highway officials, concerned about what they call the "crisis" in Northern Virginia's traffic congestion, have urged construction of an 80-mile, $770 million bypass around the Washington area's western edge.

Virginia Highway Commissioner Harold C. King sent letters to Virginia's congressional delegation this month saying it is "imperative" that Congress consider a new highway that would dissuade motorists traveling on I-95, I-70 and I-270 from getting on the congested Capital Beltway.

The Virginia Department of Highways and Transportation has developed four alternative routes for the planned road, called the Washington Area Bypass, said T. Eugene Smith of McLean, a highway commission member who has pushed the idea.

The bypass generally would extend northwest from I-95 near Dale City to an area near Dulles International Airport, cross the Potomac River near the Fairfax-Loudoun county line and connect to I-70 near Mount Airy, Md.

"I think the time has come for a public discussion of this idea," Smith said. "There is a critical situation on the Capital Beltway . . . but at this point, we have only a very, very preliminary analysis."

Virginia highway officials said they expect Maryland officials to oppose the project and that opposition could doom it.

Hal Kassoff, administrator of Maryland's State Highway Administration, said that his agency is skeptical of the plan but is considering an opposing plan "in the long term" to build a 15-mile bypass and bridge over the Potomac River from Dumfries in eastern Prince William County to Indian Head in Charles County.

One official knowledgeable about the two states' plans said he thinks the two soon will be at loggerheads over the proposals because of "economic development competition." Maryland officials would seek the southern bypass to promote Charles County development, while Virginia would favor the northern bypass for growth near Dulles, the official said.

The Virginia plan attempts to relieve congestion on the Beltway and other Northern Virginia roads, particularly to handle many of the motorists who are traveling from one state to another and whose destination is not the Washington area.

The plan is a modern version of the 1960s "Outer Beltway" plan to build a major highway around the Washington area about 10 miles beyond the existing Beltway.

Maryland and Virginia officials originally endorsed that proposal but rejected it in the early 1970s in the face of local government opposition.

Recently proposed roads, such as the Springfield Bypass in Fairfax County and the Intercounty Connector in Maryland, would take much of the traffic intended for the old Outer Beltway.

Recent heavy traffic tie-ups on the Beltway, especially on the Cabin John Bridge, persuaded Virginia officials to seek a solution, Smith said.

"We realized how very, very fragile the Beltway is in being able to withstand interruption," Smith said. A bypass "almost inevitably must be built."

Currently, about one-third of the 120,000 vehicles using the Cabin John Bridge each day are going to areas outside the local area, Smith said.

"This plan would help separate that traffic from the local traffic," Smith said.

"It's time to be thinking about these kinds of proposals," said Oscar K. Mabry, the state highway department's deputy commissioner. He said Virginia officials will ask the state's delegation in Congress to get approval for federal money to study the plan.

The federal government would pay 90 percent of the road's cost, and the states would pay 10 percent, officials said.

Rep. Frank Wolf (R-Va.) thinks the Virginia officials' highway idea is intriguing, but that "there needs to be a lot more information put forward," Wolf spokesman Jim Boyle said. "It's far too early for Congress to be considering this proposal."

Virginia officials said that even if the plan proceeded swiftly and without opposition, the highway would not be built until the next century.