Track gauge in Singapore
In Singapore, the main lines on the Mass Rapid Transit system using the 1,435 mm (4 ft 8 1⁄2 in) standard gauge.
The former KTM railway that ran from Woodlands Checkpoint to the former Tanjong Pagar Railway station uses the 1,000 mm (3 ft 3 3⁄8 in) metre gauge.
Standard gauge
Singapore's Mass Rapid Transit system uses the 1,435 mm (4 ft 8 1⁄2 in) standard gauge since the system was first constructed. Its metro lines all use the same standard gauge throughout the network. Its current metro lines using the gauge are the North South Line, East West Line. Circle Line, Downtown Line and North East Line. Future lines using the gauge are the Thomson-East Coast Line, Jurong Region Line and Cross Island Line.
The future Kuala Lumpur–Singapore High Speed Rail High-Speed Rail project from Kuala Lumpur to Jurong, Singapore will likely use the same Standard Gauge.
Other gauge
Metre gauge
The former KTM Intercity that ran from the former Tanjong Pagar Railway station to Johor Bahru used the 1,000 mm (3 ft 3 3⁄8 in) metre gauge. The tracks and depot of the line have been since removed when the service was withdrawn from 1 July 2011. The service now terminated at Woodlands Train Checkpoint, and currently only a shuttle service is run from Johor Bahru Sentral railway station to Woodlands Train Checkpoint.
Broad gauge
The current Sengkang LRT Line and Punggol LRT line are the only lines on the Light Rail Transit system to use the 1,850mm (6 ft 0⅞ in) broad gauge. The current Changi Airport Skytrain also uses the 1,850mm (6 ft 0⅞ in) broad gauge, however is not part of the Mass Rapid Transit system. Both system uses the same Mitsubishi Crystal Mover rolling stock which uses the 1,850mm (6 ft 0⅞ in) broad gauge.
Special gauges
The current Bukit Panjang LRT line is a line on the Light Rail Transit system which uses a Central guideway for control and uses the Bombardier Innovia APM 100 rolling stock. The current Sentosa Express is a monorail line not part of the Mass Rapid Transit system and uses a straddle-beam monorail system by Hitachi's straddle-beam monorail.