This polygon shapefile contains United States metropolitan planning boundaries. The United States Metropolitan Planning Organization (MPO) Database is a geographic database of MPO political boundaries and the associated agencies responsible for transportation planning, including data on MPO size and state Federal Information Processing Standards (FIPS) codes. This layer is part of the 2014 National Transportation Atlas Database. The National Transportation Atlas Databases 2014 (NTAD2014) is a set of nationwide geographic datasets of transportation facilities, transportation networks, associated infrastructure and other political and administrative entities. These datasets include spatial information for transportation modal networks and intermodal terminals, as well as the re¬lated attribute information for these features. This data supports research, analysis, and decision-making across all transportation modes. It is most useful at the national level, but has major applications at regional, state and local scales throughout the transportation community. The data used to compile NTAD2014 was provided by our partners within the United States Department of Transportation (USDOT) and by other agencies throughout the United States Federal Government. These contributors are the actual data stewards and are ultimately responsible for the maintenance and accuracy of their data. The Census Bureau designates a new list of Urbanized Areas (UZAs) every 10 years, following the conclusion of each decennial census. The designation of UZAs by the U.S. Census Bureau has significant implications for the metropolitan planning process. Federal transportation legislation requires that a Metropolitan Planning Organization (MPO) be designated for each urbanized area with a population of more than 50,000 people in order to carry out the metropolitan transportation planning process, as a condition of Federal aid. This data provides users with information about the locations, names and sizes of Metropolitan Planning Organizations and is intended for use primarily with national planning applications.