(1) The term "grade crossing" as used in this article means a crossing at grade of a public street or highway over a track or tracks of a railroad.

(2) The term "department" as used in this article means any subdivision or agency of the State having authority to locate or construct roads or streets.

(3) The term "railroad" as used in this article shall include all steam railroads and interurban electric railroads of more than twenty miles in length, which are operated as common carriers, but shall not include street railroads operated in whole or in part within the limits of any incorporated city or town or private logging roads.