Maryland Transportation Section 5-302

      (a)      This subtitle does not apply to any airport owned or operated by the United States.

      (b)      To the extent necessary and in accordance with any reasonable classification, the Administration from time to time shall exempt any other class of airports from any requirement of a rule or regulation adopted under this subtitle, if the application of the requirement would be an undue burden on the class and is not required in the interest of public safety.