King CountyFor more information about this layer please see the GIS Data Catalog . Functional classification is the process by which streets and highways are grouped into classes, or systems, according to the character of service they are intended to provide. Basic to this process is the recognition that individual roads and streets do not serve travel independently in any major way.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/40733c5a75064842b7351287f2a54e79_0engKing County GIS Open DataPublicRoad Services - Federal Function Class [Washington (State)--King County]Web servicesWashington (State)--King CountyWashington (State)Last Modified: 2026-04-24