Two long-dormant road proposals that include bridges across the Potomac River west of Washington have gotten new attention recently as officials look for ways to connect growing communities in Virginia and Maryland.

Last month, talk resumed about a bridge linking Virginia's Dulles corridor and Maryland's Interstate 270 corridor after a study by Virginia transportation officials of traffic across the American Legion Bridge.

Many Virginia officials hailed the results of the study as proof that a bridge -- dubbed the "techway" because it would connect the area's two burgeoning high-tech centers -- was needed to link workers who live on either side of the river to jobs on the opposite shore. Opponents of the bridge quickly questioned that assessment, saying the study's conclusions were based on faulty assumptions and biased results.

Last week, the Loudoun County Board of Supervisors considered putting the so-called Western Transportation Corridor back into its plans, before delaying a vote over concerns about what route the road would take in Loudoun. In its most ambitious form, the road would swing from Maryland across the Potomac through Loudoun, Prince William and Stafford counties, serving as an arc of an outer Beltway.

Plans to build more Potomac crossings west of Washington have been in and out of local and state plans for decades, shifting according to the whims of politicians on both sides of the river and the finances of state transportation budgets.

Proponents say that more bridges are needed to serve a growing number of people who commute between the booming western suburbs of Virginia and Maryland. Now, most of those people funnel across the American Legion Bridge. Backers say more bridges would relieve congestion on the Beltway, Interstate 66, I-270 in Maryland and smaller roads on both sides of the river.

Opponents argue that more roads are unnecessary and wouldn't relieve congestion anyway. Instead, they say, these routes would promote another wave of suburban sprawl that would soon overwhelm the spans and lead to more growing pains in one of the fastest expanding areas in the nation.

"It's disappointing to see how much time and money is wasted by the states at the behest of the development industry to push for projects that won't significantly relieve traffic but will significantly increase sprawl in the region," said Stewart Schwartz, executive director of the Coalition for Smarter Growth.

Bob Chase, president of the Northern Virginia Transportation Alliance, said there is a pressing need.

"The main purpose of these facilities isn't to serve future growth, it's to serve today's growth and job base," Chase said. "When you have Dulles airport and when you have the reality that most population and job growth is going to occur outside the Beltway, it's only logical that you need to provide better north-south connections between Maryland and Virginia."

Officials at the Virginia Department of Transportation said the American Legion study found that about 4,000 people make horseshoe-shaped commutes between Virginia and Maryland, the type of trip techway supporters say would be relieved by a new bridge.

Techway opponents disputed those findings in rapid-fire news releases, pointing out that areas such as Tysons Corner, which is just off the Beltway, were included as part of the U-shaped pattern. Without those job centers, the study shows that half as many cars, or about 2,000, make the west-to-east-to-west trip, they said.

VDOT "obscured the story that it's, at most, 2,000 vehicles making a U-shaped commute," said Schwartz, a leader of the anti-techway forces.

The Western Transportation Corridor has been just as hotly debated.

In a study released last week, Taxpayers for Common Sense and Friends of the Earth named the road as the 10th most wasteful highway proposal in the nation.

Erich Zimmermann, a research analyst for Taxpayers for Common Sense, said that he estimated it would cost $2 billion to build Virginia's portion of the road from Stafford to Loudoun and that the road wouldn't solve the area's traffic needs.

"Much of the problem for traffic in that area is east-west, not north-south," Zimmermann said. "If the project isn't going to be effective, that's the number one concern for taxpayers."

The Loudoun board, which was to vote June 1 on whether to restore the road to county plans, instead sent the question back to the county's Planning Commission for further study.

Members of the board's Republican majority had signaled their intention to revive the highway proposal in a vote at their first meeting in January, but community opposition has shaken some supervisors' support. It remains unclear how the board will vote on the matter when members take it up again in the coming months.

Supervisor Bruce E. Tulloch (R-Potomac), who had earlier backed the road's restoration, now says he wants to see route changes that would steer the proposed highway around established neighborhoods.

"There are several affected communities where the road runs right through them," Tulloch said.

Staff writer Michael Laris contributed to this report.