{"id":"S2007009878","label":"Traffic signal preemption","description":"","source_url":"https://id.loc.gov/authorities/subjects/sh2007009878","normalized_label":"traffic signal preemption","broader":["http://id.loc.gov/authorities/subjects/sh2006004340"],"aliases":["Preemption, Traffic signal","Signal preemption, Traffic","Signal priority systems, Traffic","Traffic signal priority systems"],"source_identifier":"http://id.loc.gov/authorities/subjects/sh2007009878","provider":"lcsh","revision":"2ed96a65e5ad1582","taxonomy_revision":"f050b5d4780b1289","title":"Traffic signal preemption","url":"/topics/S2007009878","kind":"topic-directory","aeo_cohort":"topic-directory","catalogue_revision":"f050b5d4780b1289","numeric_address":"5190539592075469348","address_version":"morton4x16-v1","coordinates":[0,478,33321,22528],"answer_status":"Directory metadata; local answer requires separate source review","truth_status":"Subject descriptor, not a factual answer or a demonstrated knowledge gap","reviewed_answer":null}