A
viaduct is a
bridge composed of several small spans for crossing a valley or a gorge. The term
viaduct is derived from the
Latin via for road and
ducere, to lead. The
ancient Romans did not use the term; it is a modern derivation from an analogy with
aqueduct. Like the
Roman aqueducts, many early viaducts comprised a series of arches of roughly equal length. Viaducts may span land or water or both.