The canonical URI is defined for each instance of an Infrastructure element, e.g. section of line, operational point, track, tunnel, siding. Objects of the infrastructure generated through RML mappings include (when provided) their validity start and end dates. With its identifier, plus all identifiers of its "parent" elements, and its validity dates, a hash URI is generated. The canonical URI is the element's URI with its identifiers and without the validity dates. All of the hash URIs of an element point to its canonical URI. Additionally, SoLs point to the canonical URIs of their start OP and end OP.