Representatives from the Maryland State Highway Administration briefed the Montgomery County Planning Board on the idea of adding "Express Toll Lanes" to the Maryland side of Interstate 495 currently under consideration to ease gridlock on the heavily congested Beltway. But after hearing the estimated cost of $3 billion to $4 billion and the relocation of up to 40 homes and businesses required to complete the project, commissioners were skeptical of its merits.

"If you invest this $3 billion, take these 40 homes and tie up traffic during the course of construction for years, and then you get an increase in capacity, how long does that increase in capacity last before it's eaten up and you're back to where you started?" Planning Board Chairman Derick P. Berlage said.

But increasing mobility -- not capacity -- is the goal, Raja Veeramachaneni, director of the State Highway Administration's Office of Planning and Engineering, told commissioners. The additional capacity is the means of getting there, he said.

"Mobility is being able to make a reliable trip when you need to," he said. "You may have to pay more, but you'll get there."

The current plan would add two Express Toll Lanes, one in each direction on the Beltway, and require the road be widened in some areas. One existing general lane on either side also could be converted into a toll lane.

The Beltway's Express Toll Lanes, which would extend about 42 miles from the American Legion Bridge to the Woodrow Wilson Bridge, would provide a reliable travel time for people willing to pay to reach their destination faster and present new mass transit alternatives, Veeramachaneni said.

"The toll lanes could be used for running express bus service. Right now if you want to run buses on the Beltway, they would be stuck along with the rest of the traffic," he said.

The administration is proposing direct-access ramps to the toll lanes at the I-270 east and west spurs, I-95 and U.S. Route 50. Tolls would be collected electronically and would vary based on demand both during rush hours and actual traffic conditions throughout the day. The tolls would increase when the lanes are relatively full, for example, and decrease when there is additional capacity.

A similar system in San Diego's eight-mile "FasTrak" express lanes charges tolls varying from $1 to $4, but it is unknown what the actual cost of tolls would be in Maryland.

The $900 million Virginia Beltway widening project approved last week would add two HOT lanes in each direction, stopping short of the American Legion Bridge. It will be paid for by private contractors.

Maryland officials dropped studies of adding two additional lanes in each direction in the 1990s due to the costs and community impacts.

The agencies are still in the planning phase of the project and are several years away from any construction. Officials expect to complete the Draft Environmental Impact Statement sometime over the summer before holding a public hearing in the fall and seeking approval for the project in fall of 2006. The state also has proposed toll lanes on I-270 and a stretch of I-95 in Baltimore.

Both the Montgomery County Council and County Executive Douglas M. Duncan supported studying widening the Beltway in a July 2004 letter to Maryland Transportation Secretary Robert L. Flanagan.

In 2003, the council voted in favor of widening the Beltway for a single HOV or HOT lane in each direction from the I-270 spur to the American Legion Bridge, but has not endorsed widening the Beltway east of I-270.

One of the main concerns of the commissioners on was the loss of up to 40 homes in the Forest Glen neighborhood of Silver Spring and Locust Hill in Bethesda that the state would be required to purchase and relocate if the project moved forward.

"As much as I am in favor of this, the reality is, where could you go for whatever we pay folks to replace those residences and still be within the Beltway?" Commissioner Allison Bryant said.

"Where could they go and walk to the Metro station, which is right across the street?" Commissioner John M. Robinson added.

Based on the agency's presentation Thursday, Berlage said he remained unconvinced the potential gain of the expansion would outweigh the loss.

"I guess the overwhelming sense of frustration that I have...is the feeling that this is yesterday's solution," Berlage said, "to expand the road at enormous cost and enormous disruption, taking 30 to 40 people's homes away from them, to achieve an improvement, the significance of which is an open question. At this point, it seems doubtful to me that this is a worthwhile investment. But I know the study will continue and we're not making a decision today."