What are Federal-Aid Urban Areas (i.e., Urbanized and Small Urban Areas)?
The Census Bureau and FHWA have slightly different definitions for the term Urban Area. The Census Bureau uses the term Urban Area to refer to the Urbanized Areas and Urban Clusters designated by the Census Bureau. FHWA uses the term Federal-Aid Urban Area to refer to the “adjusted” or “smoothed” Urbanized Areas and Small Urban Areas that are used for transportation planning purposes. Federal-Aid Urban Areas are based on the Census designated Urban Areas. FHWA allows the responsible state and local officials, in cooperation with each other and subject to approval by the Secretary, to “adjust” or “smooth” the Census designated Urban Area boundaries outward to delineate the Federal-Aid Urban Area boundaries. FHWA requires state transportation departments to update their Federal-Aid Urban Areas based on the Census Bureau’s decennial census data. The “adjusting” or “smoothing” of Urbanized and Small Urban Area boundaries is a way of expanding Census defined boundaries to better reflect loc
