N.D. Cent. Code § 40-56-03

When any city has, by ordinance, established standards of paving for residential areas, the city as a whole, by action of its governing body, may pay not to exceed twenty percent of the cost of the paving, and if because of heavy traffic upon such street or for other valid reason, the governing board determines that the established standards should be exceeded in any portion of a residential paving project such percentage of the excess cost of paving as may be determined by action of the governing body shall be borne by the city as a whole.