Maryland Tax - General Section 11-223

      The sales and use tax does not apply to a sale of:

            (1)      a bus to a person who uses the bus only:

                  (i)      in the operation of the transportation system of a political subdivision of the State; and

                  (ii)      for public transportation on regular schedules and between fixed termini, as defined in Title 11 of the Transportation Article; or

            (2)      a transportation service.