State Highway Network Lines

StateHighways are state highways based upon the Caltrans Linear Referencing System. Each record in this layer represents a highway segment where the county, route, postmile prefix, and postmile suffix are the same. Each segment has a begin and end postmile. This geometry is based upon the extraction from TSN on 8 June 2025. Route geometry updates based upon this extraction include routes 3, 36, 38, 49, 89, 139, 174, and 221. All updates received an update date of 6/8/2025 except for route 221 which received a date of 7/1/2025.