Bridges and Viaducts

Bridges, viaducts and aqueducts in this atlas's Transportation Buildings subcategory, infrastructure rather than buildings in the strict sense, following the report's own judgment that they fit this subcategory's transportation-mode scheme anyway. Belongs here: any bridge, viaduct or aqueduct this atlas records under this subcategory, and the Causeway article describing the same family of raised road or rail crossings over water or low ground. Does not belong here: a building proper of any of this subcategory's other four modes.