Two road-construction teams claim they can add nearly $1 billion worth of extra lanes to Interstate 95 between Washington and Massaponax without spending a dime of state money.

A panel of state and regional transportation officials will spend the next six months evaluating the proposals to see if either is realistic.

The plans have existed in sort of a preliminary fashion for more than a year, with both teams offering to build High-Occupancy Toll lanes--or HOT lanes--from Northern Virginia to the Fredericksburg region.

But each submitted a more detailed plan to the Virginia Department of Transportation yesterday, painting clearer pictures of how they hope to break up congestion without using taxpayer dollars.

Fluor/Transurban's $913 million proposal would convert the existing two HOV lanes in Northern Virginia to three HOT lanes. Cars with three or more occupants would have free access to the facility, which would start at the 14th Street Bridge, but other motorists would pay to use it.

The Fluor/Transurban plan would also build two HOT lanes from Dumfries down to Massaponax and add six 500-space commuter lots along the I-95 corridor, including one each in Spotsylvania, Fredericksburg and Stafford.

The other proposal, submitted by Clark Construction and Shirley Contracting Co., would provide three HOT lanes from the 14th Street Bridge to State Route 610 in North Stafford and then two such lanes down to U.S. 17 in southern Stafford.

From there, the team would build a series of collector-distributor lanes and extra travel lanes on the mainline of I-95 to help move traffic between U.S. 17 and the congested Massaponax area. Those lanes would be open to all motorists free of charge.

The Clark/Shirley plan would cost about $815 million. Originally, that proposal stopped at U.S. 17 in Stafford with an option to add improvements south of there.

After looking at traffic counts in Spotsylvania, the group is set on providing extra highway capacity all the way to Massaponax, said Clark Bottner, project director with Shirley Contracting Co.

"They're not options," he said. "They're not maybes. They're definites."

Both groups also provide some cash. Fluor/Transurban would give VDOT $250 million upfront or about $510 million over 60 years--the arrangement is up to VDOT--to invest in public transportation options, like commuter buses and trains.