An island platform (also center platform (American English) or centre platform (British English)) is a station layout arrangement where a single platform is positioned between two tracks within a railway station, tram stop or transitway interchange. Island platforms are sometimes used between the opposite-direction tracks on twin-track route stations as they are cheaper and occupy less area than other arrangements. They are also useful within larger stations, where local and express services for the same direction of travel can be accessed from opposite sides of the same platform instead of side platforms on either side of the tracks, simplifying and speeding transfers between the two tracks.