Various structural elements are associated with the Railway dataset.

The following are ‘crossings’ being a point feature class representing structures that facilitate the crossing of a road or railway over, under or through another feature.

Rail Bridge: a structure erected over a depression or obstacle to carry a railway.

Rail Tunnel: an underground or underwater railway passage.

Rail Culvert; a masonry conduit which serves as a channel-crossing for water or a transport network beneath a railway.

Note the ‘ontype’ attributes of railway features which have an obvious topological link to these features.