Subway riders on the Nos. 1, 2 and 3 lines face service changes this week and next as part of the MTA's Fastrack repair program.

No trains on those lines will run between 34th Street-Penn Station and the Atlantic Avenue-Barclays Center stops or, in the case of the No. 1 train, South Ferry, overnight between Monday and Friday.

From 10 p.m. to 5 a.m. each night, the No. 1 train will only run between 242nd Street-Van Cortland Park and 34th-Street Penn Station.

The No. 2 train will only run between East 180th Street in Van Nest and 34th Street-Penn Station; it will operate on the No. 5 line between Dyre Avenue and East 180th Street.The No. 3 train will be completely suspended.

The MTA is running shuttle buses at the 148th Street, 145th Street and 135th Street stations in Harlem. The No. 4 line will make all No. 3 train stops in Brooklyn between Atlantic Avenue-Barclays Center and New Lots Avenue.

The second week of Fastrack repairs will begin Monday, August 24, and end Friday, August 28.

The MTA cleans and removes debris, maintains its signal system, and does repair work and painting at stations during Fastrack work.