An
elevated railway (also known in Europe as
overhead railway) is a
rapid transit railway with the tracks above street level on a viaduct or other steel, concrete or brick structure. The railway may be
standard gauge,
narrow gauge,
light rail,
monorail or a
suspension railway. Elevated railways are usually used in urban areas where there would otherwise be a large number of
level crossings. Most of the time, the tracks of elevated railways that run on steel viaducts can be seen from street level.