(a) The political subdivisions of this State have full authority, under their respective zoning powers: (1) To zone areas for commercial or industrial purposes; and (2) In these areas, to govern the size, spacing, and lighting of outdoor signs. (b) Notwithstanding any provision of this part or any rule or regulation of the Administration: (1) Local zoning regulations that relate to outdoor signs in commercial or industrial areas shall govern within the zoned area; and (2) If a political subdivision adopts comprehensive zoning that includes the regulation of outdoor signs: (i) The Administration may so certify to the Federal Highway Administrator; and (ii) On certification, the control of outdoor signs in commercial or industrial areas transfers to the political subdivision.
Maryland Legal Code