The feature geometry for Statewide Highways are centerlines that contain directional attributes. Therefore, to display attributes based on directionality, features must be symbolized separately using related directional fields and/or attributes. The "left" direction corresponds to southbound and westbound features; the "right" direction corresponds to northbound and eastbound features. The DIR field indicates the basic directionality associated with the feature.

Per the Caltrans Trash Assessment Methodology (TAM), highway segments were attributed with 2024 trash generation ratings based on Combined Score, Overland Visual Trash Assessment (OVTA), or Integrated Maintenance Management System (IMMS) methodologies. Please refer to the most recent TAM for more information on trash generation ratings and their application.

2024 trash generation ratings are split between LTrashGenRating2024 and RTrashGenRating2024 fields. Features in this map are displayed using an "offset" to help the user visualize left vs. right directional features and their associated trash generation ratings. Each highway centerline record is also coded with the district, county, and route information, along with postmile prefix (if any), postmile, and postmile suffix (if any). Additional attributes related to stormwater compliance have been added. Refer to the Resource > Lineage, Resource > Lineage > Process Step, and Resource > Fields sections of this metadata for additional details.

This feature layer does not include areas within CA Regional Water Quality Control Board 2 or Los Angeles Trash Total Maximum Daily Loads (TMDLs); for more information on those areas please refer to the California Water Boards website at https://www.waterboards.ca.gov/.