Standard gauge
rail track gauge – international standard gauge (1435 mm, 4 ft 8 1⁄2 in)
The standard gauge (also called the Stephenson gauge after George Stephenson, or normal gauge) is a popular rail gauge. About 60% of the world's current railway lines use this gauge. The distance between the inside edges of the rails of standard gauge track is 1,435 mm (4 ft 8 1⁄2 in).
