Linked from
The 8 pages that link to Viaduct, each with the reason it gives.
BridgeBroader topic: Viaducts extend bridge construction across broad valleys and uneven terrain.
Bridge pierBroader topic: Its repeated spans commonly rest on a line of piers.
Railway bridgeRelated: Railways use viaducts to maintain a steady gradient across broad terrain.
Trestle bridgeNarrower topic: A trestle bridge can form a viaduct from repeated short supports.