Streets and Highways Code § 661

In addition to persons, public corporations, and districts specified in this chapter, this chapter shall apply to all private corporations authorized by law to establish or maintain any works or facilities in, under or over any public highway. This chapter shall not limit the powers and duties vested by law in the Public Utilities Commission of this State, and in the event of any conflict with regard to the powers and duties given the department in this chapter, those of the Public Utilities Commission shall prevail.