Metro is planning another major shake-up of its bus routes beginning Sunday, when more than 70 routes will be realigned to provide better connections with the new Orange Line subway stations in Arlington.

Most of the metrobus service that presently terminates at the Rosslyn station will be transferred to the Ballston station, which opened Dec. 1 as an Orange Line terminal.

Generally, all bus routes in a wedge between Columbia Pike and Little River Turnpike on the south, Fairfax City on the west and the Potomac River on the north will be affected.

The changes will mean higher subway fares and lower bus fares for most commuters who presently use the Rosslyn station as a transfer point. That is because Rosslyn is within a small bus-fare zone, while Ballston is outside the zone. Thus, one zone charge will be eliminated on the bus fare. However, since subway fares during rush hour depend on the distance traveled, and since Ballston is farther from downtown Washington and other locations on the subway than Rosslyn, the subway fare will be somewhat higher for many people.

Some bus service will continue along the Wilson Boulevard-Fairfax Drive corridor that the Orange Line serves. Local buses will continue to cross the Potomac River at Key Bridge, but almost all cross-Potomac rush-hour express buses will be eliminated.

Metro has made similar service adjustments at other major subway terminals as other sections of the subway have opened.