An elevated railway or elevated train is a railway with the tracks above street level on a viaduct or other elevated structure. The railway may be a broad-gauge, standard-gauge or narrow-gauge railway, rapid transit, light rail, monorail, or a suspension railway. Elevated railways are normally found in urban areas that would otherwise require impracticably many level crossings. Usually, the tracks of elevated railways that run on steel viaducts can be seen from street level.