The M1 and M3 are two similar series of electric multiple unit rail cars built by the Budd Company for the Long Island Rail Road, the Metro-North Railroad, and Metro-North's predecessors, Penn Central and Conrail. Originally branded by Budd as Metropolitans, the cars are more popularly known under their model names, M1 (late 1960s/early 1970s cars) and M3 (mid-1980s cars). The Metro-North cars were branded under the M1A and M3A series.
