The provisions of this chapter shall not apply to:
(1) Construction, reconstruction, operation or maintenance by an authorized person of overhead electrical or communication circuits or conductors and their supporting structures, or to electrical generating, transmission or distribution systems, or to communication systems;
(2) Agreements between public agencies to perform any work or undertaking which each public agency entering into the agreement is authorized by law to perform, provided that any such agreement shall be authorized by the governing body of each party to the agreement; or
(3) Fire, police or other emergency service workers while engaged in emergency operations, or highway districts or other governmental entities performing routine or emergency maintenance in their rights of way.