Relief for Recovering Communities Act This bill requires the Department of Transportation to treat an area as an "urbanized area" following a major disaster under the Disaster Relief Act of 1974 until the second decennial census conducted after such disaster if: (1) the area was defined and designated as such by the Department of Commerce in the decennial census immediately preceding such disaster, effective with the 2000 decennial census; and (2) the population of the area fell below 50,000 as a result of such disaster. This designation as an urbanized area permits an application for federal transit funding based upon population levels in the area prior to the major disaster. An area treated as an urbanized area shall be assigned the population and square miles of the urban cluster designated by Commerce in the most recent decennial census.