In model railroading, toy trains larger than O gauge that operate on track measuring 2-1/8 inches between the running rails. Standard Gauge products were introduced by the Lionel Corporation in 1906 and were commonly produced by Lionel and others up until the start of World War II. In prototype railroading in the U.S. (and in some other countries), track measuring 4 feet, 8-1/2 inches between the inside edges of the running rails.
A standard gauge railway has track with 4 foot 8½ inches (1435mm) between rails.
railroad track having the standard width of 56.5 inches
The UK standard gauge is 4 foot 8½ inches. Anything wider is referred to as broad gauge, and anything narrower as narrow gauge.
The Track Gauge is the distance between the rails of a track; measured from inside edge to inside edge of the rail head. Standard Gauge is the most widely used 4' 81/2" (or 1,435mm). Top of Glossary
The original track gauge first used by the ancient Romans and adopted by early railway builders in England.
As applied to railway track, the distance of 4 feet 82 inches measured between the heads of the running rails.
As railways developed and expanded one of the key issues to be decided was that of the rail gauge (the distance between the inner sides of the rails) that should be used. The eventual result was the adoption throughout a large part of the world of a standard gauge of 1435 mm (4 ft 8½ in), allowing inter-connectivity and the inter-operability of trains. Currently 60% of the world's railway lines are built to this gauge.
