ALEXANDRIA, Va. (AP) – The last major blitz of Metro track repair and maintenance in northern Virginia is now under way.

Work on Metro’s blue and yellow lines will lead to shutdowns and slowdowns in Arlington and Fairfax counties and the city of Alexandria for the next month. Riders on both lines are being urged to seek alternatives.

Metro is coming down the homestretch of a yearlong effort to bring its tracks back to a state of good repair. There are three more areas where work is planned under the SafeTrack program through June. Those places are all in Maryland and the District of Columbia, and the exact dates for the work have not yet been set.

Ridership on Metro has dipped during the maintenance blitz, contributing to the transit agency’s budget woes.