Staten Island Railway

The Staten Island Railway (SIR) is the only rapid transit line in the New York City borough of Staten Island. It is operated by the Staten Island Rapid Transit Operating Authority (SIRTOA), a subsidiary of the New York City Transit Authority, which in turn is an agency of the Metropolitan Transportation Authority. Although the railway is considered a standard rail line, only the western portion of the North Shore Branch (which is used by freight) is connected to the national rail system. The passenger operations, however, are regulated as a rapid transit system, and exempt from certain regulations such as installing positive train control signals (the railroad currently uses automatic train control signals installed in 2005).

SIR operates 24 hours a day, seven days a week, providing local service between St. George and Tottenville, along the east side of the borough. While it uses modified R44 New York City Subway cars, there is no direct rail link between the SIR and the subway system. SIR riders receive a free transfer to New York City Subway lines, however, and the line is included on official New York City Subway maps. Fares are only collected from passengers boarding and exiting at the Tompkinsville and St. George stations. Commuters on the railway typically use the Staten Island Ferry to reach Manhattan; the line is accessible from within the Ferry Terminal, and most of its trains connect with the ferry.

The line has a route bullet similar to other subway routes: the letters SIR in a blue circle. It is used on timetables, the MTA website and some signage. The SIR bullet is shown at signage at the new Arthur Kill station.}} but not on trains. The line runs 24 hours a day every day of the year, and is one of only six 24/7 mass-transit rail lines in North America; the others are the PATCO Speedline, the Red and Blue Lines of the Chicago "L", the PATH lines, and the New York City Subway.

In addition to full-time local service, the Staten Island Railway also runs a weekday peak-direction express service. On weekdays, express service to St. George is provided from 6:15 to 8:15 a.m. and to Tottenville from 7:01 to 8:01 a.m. and 4:01 to 7:51 p.m. Morning express trains run non-stop in both directions between New Dorp and St. George; afternoon express trains run non-stop southbound from St. George to Great Kills.