This polygon shapefile contains the California Metropolitan Transportation Commission's (MTC) Communities of Concern (COC) for the San Francisco Bay Area (TAZ 1454 geography) based on eight ACS 2005-2009 tract-level variables: Minority, Low-Income (less than 200% of federal poverty level), Level of English proficiency. Elderly, Zero-Vehicle Households, Single Parent Households, Disabled, Rent-Burdened Households. If a tract exceeds a threshold value for four or more variables, it is a COC. 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.