California Code, Streets and Highways Code - SHC § 685

In case a franchise is granted for the exercise of a privilege in a city street or county highway, approval of the department shall not be required in respect to intersections.  Franchises may be granted extending across the common area of the intersection without any such approval.  In cases where the grades of the state highway and the city street or county highway are separated, the franchise shall be exercised only on the city street or county highway.