The provisions of this Subtitle shall govern the operation for hire in Prince George's County of any taxicab, excepting motor vehicles owned and operated by the Washington Metropolitan Area Transit Authority and those licensed by the Public Service Commission of the State of Maryland to operate on fixed routes and schedules and except any vehicle operated by any funeral director duly licensed by the State Board of Funeral Directors and Embalmers of Maryland, and further excepting any funeral livery service licensed as such by the Department of Motor Vehicles of Maryland while said vehicle is being operated for the purpose of funeral services or transportation incidental thereto.