Virginia transportation officials approved a route for a new outer-county highway yesterday, clearing another hurdle in their efforts to build a north-south road through Northern Virginia's booming suburbs.

The Commonwealth Transportation Board chose a route for the tri-county parkway that would begin where the Route 234 bypass hits Interstate 66, west of Manassas National Battlefield Park, and run directly north to the Loudoun County line.

The board also directed the Virginia Department of Transportation to seek private sector proposals to finance the $201 million cost of the 10.4-mile highway because the state has no money to build it. If a private developer built the road, drivers would pay tolls to use it.

"This means that project development for this alignment can proceed," said Virginia Transportation Secretary Pierce R. Homer. "But there's extremely limited available funding to even do the next phase of planning or engineering, and there's no funding for right-of-way acquisition or planning or construction."

Next the federal government must complete an environmental review and decide whether the highway should be built. That decision is expected by the end of 2006.

State officials and other parkway supporters say the road is critical to link the Dulles business corridor with the growing residential communities of Prince William and Loudoun counties. Chronically crowded Route 28 is the primary north-south connection; otherwise drivers must take a series of country roads.

But some parkway supporters said the chosen route is too far west to ease traffic on Route 28.

"We're surprised by their decision and disappointed," said Prince William Board of County Supervisors Chairman Sean T. Connaughton (R). A preferable route would run east of the park and ease daily jams on Route 28 between Manassas and Centreville, Connaughton said.

"This alignment will not really do anything for Route 28 in Prince William," he said.

Connaughton added that the chosen route veers from the original intent of the road because it no longer goes through Fairfax County. "With this vote, we go from a tri-county parkway to a bi-county parkway," he said.

The road would terminate at the Loudoun line, where there is no connection to other major roads. Other alignments would have stretched it as far north as Route 50.

Transportation Board member Katherine K. Hanley said the panel voted for the route because the other ones had too many complications, particularly the eastern route, which would have sliced through a local park.

"I thought it was better to support a project that can actually get built and help address traffic problems than fight about one that has a very slim chance of ever getting constructed," she said.

Those who have urged VDOT to scrap plans for the highway, saying it would cause more suburban sprawl in an area teeming with new development, were also disappointed with the route.

Stewart Schwartz, executive director of the Coalition for Smarter Growth, said the tri-county decision and the approval yesterday of a similar road in Hampton Roads "symbolize everything that's still wrong with the Virginia Department of Transportation. They've got nothing to do with traffic relief and everything to do with opening new land to development."