Northern Virginia business leaders are attacking an $11 billion regional transportation plan drawn up by local politicians because they say it proposes building too much mass transit and too few roads and Potomac River bridges to serve the area's growing population.

The criticisms come as a group that includes all elected Northern Virginia leaders prepares to vote on the "20/20 Plan" on Dec. 16. The officials aim to use the plan as a blueprint for funding during the General Assembly session that begins next month.

"To leave off the table something as fundamental as bridges is incredible," said Robert Chase, the director of the Northern Virginia Transportation Alliance. "If you think about it, the fundamental deficiency is a lack of alternatives. If one guy decides to stand on a bridge, or one truck tips up on the Beltway, there's no place for people to go."

Chase, officials at the Greater Washington Board of Trade and others said that the plan is too dependent on mass transit. Adding new Metro stations and light rail lines to the region will not solve the area's gridlock unless there also are new roads and bridges that drivers can use to cross into Maryland, critics say.

Developer John T. "Til" Hazel complained in a recent letter to a high-tech business group that mass transit projects in the plan--which include light rail lines between Manassas and Dulles International Airport and between the Pentagon and Baileys Crossroads--would cost $160,000 per worker.

"By no stretch of the imagination is such investment for so little return justifiable," Hazel wrote.

Defenders of the plan said yesterday that its projects would provide significantly improve the region's transportation network. And they noted that it represents the first time every Northern Virginia jurisdiction has agreed on a single, comprehensive package of improvements.

Kenneth Klinge, the chairman of the Transportation Coordinating Council of 28 elected officials and 10 state legislators, said its critics are shortsighted to dismiss it entirely.

"Does it solve all the problems?" he said. "No. But it sure makes a pretty good start at solving the problems."

And Klinge said the council may yet respond to the pressure from business groups and include new Potomac River bridges before taking the final vote on the plan. The issue was discussed by the panel last month, he said.

"To say it's not going to include bridges is not correct," Klinge said. "It may or may not. Bridges are being discussed."

Fairfax Board of Supervisors Chairman Katherine K. Hanley (D), a member of the council, said she supports changing the plan to reflect the need for new bridges. But she noted that Maryland politicians have steadfastly opposed new bridges into Maryland.

"The Fairfax board is on record including those," she said.

That doesn't please everyone.

Environmentalists and others have praised the 20/20 Plan because it relies heavily on mass transit rather than new construction. Stuart Schwartz, director of the Coalition for Smarter Growth, said building new bridges would encourage a new western Beltway bypass, something he opposes.

"The Board of Trade and Mr. Hazel have not veered one iota from their long-term goal of an outer beltway," Schwartz said. "The bottom line: Studies have shown the western bypass will not relieve congestion on the Beltway, I-95, I-66 or the Dulles Toll Road."

Schwartz said his group believes that the 20/20 Plan should continue to focus on mass transit, but with greater attention to the impact that land-use and development decisions can have on traffic.