<P> A standard - gauge railway is a railway with a track gauge of 1,435 mm ( 4 ft 8 ⁄ in ) . The standard gauge is also called Stephenson gauge after George Stephenson , International gauge , UIC gauge , uniform gauge , normal gauge and European gauge in the EU and Russia . It is the most widely used railway track gauge across the world with approximately 55 % of the lines in the world using it . All high - speed rail lines , except those in Russia , Finland , Portugal and Uzbekistan , use standard gauge . The distance between the inside edges of the rails is defined to be 1435 mm except in the United States , where it is still defined in Imperial and US customary units as approximately 4 ft ​ 8 ⁄ in . </P>
<P> A standard - gauge railway is a railway with a track gauge of 1,435 mm ( 4 ft 8 ⁄ in ) . The standard gauge is also called Stephenson gauge after George Stephenson , International gauge , UIC gauge , uniform gauge , normal gauge and European gauge in the EU and Russia . It is the most widely used railway track gauge across the world with approximately 55 % of the lines in the world using it . All high - speed rail lines , except those in Russia , Finland , Portugal and Uzbekistan , use standard gauge . The distance between the inside edges of the rails is defined to be 1435 mm except in the United States , where it is still defined in Imperial and US customary units as approximately 4 ft ​ 8 ⁄ in . </P>
what is the standard width of train tracks
what is the standard width of train tracks
1,435 mm ( 4 ft 8 ⁄ in )
1,435 mm ( 4 ft 8 ⁄ in )