This polygon shapefile represents California Department of Transportation (Caltrans) districts in California as of 2015. Caltrans has 12 districts and 2 regions as high-level management areas. As of Nov. 1, 2015, District 9 has become an independent district separate from the Central region. These boundaries are primarily based on the county boundaries. Census TIGER/Line county data from 2010 were used to create this layer. This layer is part of a collection of GIS data created by the California Department of Transportation (Caltrans).This dataset is intended for researchers, students, and policy makers for reference and mapping purposes, and may be used for basic applications such as viewing, querying, and map output production, or to provide a basemap to support graphical overlays and analysis with other spatial data.