There is no 1, 2, 3 service in Tribeca for the weekends through August 24 so the agency can replace switches. 1 train will not operate south of 14th Street2 train will only run between Eastchester-Dyre Avenue and Penn Station3 train is fully suspended. 4 trains will replace 3 trains between Crown Heights-Utica Av and New Lots Avenue all weekend. The new switches, the MTA said, will provide better service reliability and on-time performance.) Service changes go into effect starting Fridays at 9:30p through Mondays at 5a.