This polygon shapefile contains the traffic analysis zones (TAZs) for the San Francisco Bay Area in California. These data have been clipped to the shoreline for cartographic representation. TAZs are special-purpose geographic entities delineated by state and local transportation officials for tabulating traffic related data from the decennial census, especially journey-to-work and place-of-work statistics. A TAZ usually consists of one or more census blocks, block groups, or census tracts. Each TAZ is identified by a 6-character alphanumeric census code that is unique within county or statistically equivalent entity. A code of ZZZZZZ indicates a portion of a county where no TAZs were defined. This layer is part of the Bay Area Metropolitan Transportation Commission (MTC) GIS Maps and Data collection. 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. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.