Question: How many maintainers are there of the bridges that can carry motor vehicles over them?
SPARQL query:
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x prop:carries <http://dbpedia.org/resource/Motor_vehicle> . ?x onto:maintainedBy ?uri  . }