<http://schema.org/keywords>
"highway, road, pavement, Autobahn, Stra\u00DFen, Pflaster, autoroute, route, trottoir, estrada, cal\u00E7ada"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.bibliocad.com/library/rail-crossing--details_30095>