Cal. Streets and Highways Code § 1450

As used in this chapter: (a) The term “highway” includes all or any part of the entire width of right of way of a county highway, whether or not such entire area is actually used for highway purposes. (b) The term “encroachment” includes any tower, pole, poleline, pipe, pipeline, driveway, private road, fence, billboard, stand or building, or any structure or object of any kind or character not particularly mentioned in this section, which is placed in, under or over any portion of the highway. (c) “Public agency” includes any city, public corporation, political subdivision, or district. (d) “Road commissioner” means the county road commissioner appointed pursuant to Section 2006. This chapter shall only apply to any works or facilities of any public agency or public utility if such works or facilities are installed pursuant to franchise 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 road commissioner in this chapter, those of the Public Utilities Commission shall prevail.