The Long Island Rail Road , often abbreviated as the LIRR, is a commuter rail system in the southeastern part of the U.S. state of New York, stretching from Manhattan to the eastern tip of Suffolk County on Long Island. With an average weekday ridership of 354,800 passengers in 2016, it is the busiest commuter railroad in North America. It is also one of the world's few commuter systems that runs 24/7 year-round. It is publicly owned by the Metropolitan Transportation Authority, which refers to it as MTA Long Island Rail Road.