Island County GISCounty roads with Average Daily Trip (ADT) values. ADT values are from a variety of sources, including actual counts and estimates. ADT data is stored on the Mobility road management software and data system established by the Washington County Road Administration Board (http://www.crab.wa.gov/Technology/Mobility/).ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/9dd88c8ab15e4047a6fb51a7af493d05_0engIsland County Open Data PortalPublicAverage Daily Trips [Washington (State)--Island County]Web servicesWashington (State)--Island CountyWashington (State)Last Modified: 2026-01-08