Overview of Urbanized areas By pbmpo
Urbanized area A Census-designated urban area with 50,000 residents or more.
Adjusted urbanized area A Census-defined UZA boundary that has been adjusted by a State DOT to include additional territory. Typically created to smooth irregular UZA boundaries
Sources: https://www.fhwa.dot.gov/planning/census_issues/urbanized_areas_and_mpo_tma/faq/page01.cfm#Urbanized_Area_UZA https://www.fhwa.dot.gov/planning/processes/statewide/related/highway_functional_classifications/section06.cfm