Metro General Manager Richard Page has proposed that 15 of its Northern Virginia commuter bus routes across the 14th Street bridge be terminated at the Pentagon this spring, when Metrorail's Yellow Line is expected to start running from the Pentagon to Gallery Place.

The plan, the Metro staff's latest attempt to boost subway traffic by canceling "duplicate" bus routes, would force thousands of Washington commuters to transfer from suburban buses to the subway at the Pentagon, adding to their daily commuting costs. Current bus traffic across the 14th Street bridge would be virtually eliminated, except for a new route No. 13 that would serve as a Washington-Pentagon shuttle.

The proposed cutoffs would begin in May, a month after Yellow Line service from National Airport to Gallery Place is tentatively scheduled to begin. The Metro board has agreed to set up three public hearings on the closings in Northern Virginia next month.

Under Page's plan, bus routes 6, 7, 8, 9, 12, 14, 15, 16, 17, 18, 19, 21, 27, 28G and 29 would converge at the Pentagon, ending all bus service into Washington from Alexandria and the southern and eastern part of Fairfax County. Route 13A would cross into the District via Memorial Bridge and return over the 14th Street bridge, while 13B would run in the opposite direction.

Fairfax board chairman John F. Herrity said he is skeptical of the proposal. "Someone would have to convince me it wouldn't result in more ridership losses," he said. "Sometimes people vote with their feet."

He said "taking all the convenience out of riding the bus" would lead to more "ad hoc car pools," especially with the opening of I-66.

Metro spokeswoman Marilyn Dicus said the proposed Yellow Line adjustments are similar to the rerouting of some western Fairfax buses that followed the opening of the Blue Line in Rosslyn. Despite protests about the closings at that time, Dicus says Metro recorded an overall gain in the number of riders.