What track gauge do Japan’s Shinkansen high-speed trains use?

Japan’s Shinkansen high-speed trains use a 1,435-millimetre track gauge.

This is known as standard gauge, the same gauge used by most high-speed railways worldwide. Japan’s older conventional railway lines generally use the narrower 1,067-millimetre narrow gauge, so building Shinkansen lines on standard gauge helped create a separate high-speed network.

The gauge is the distance between the inner faces of the two rails. It is not the same as the train’s body width, wheel diameter, or maximum speed. The dedicated Shinkansen network also uses specially engineered alignments, grade-separated crossings, and advanced signalling.

A related exception is the Yamagata and Akita Shinkansen services, which use some converted conventional routes with narrower track. Their trains are designed to run on both standard-gauge Shinkansen track and those local routes.