Cal. Sts. & Hy. Code § 112
The department may enter into an agreement with any city relative to proceedings to be taken by the city to fix or change the grade of any State highway, or portion thereof, within the city in order to establish a grade specified in such agreement. The city, in fixing such grade, may follow the procedure specified in any statute or ordinance providing for fixing or changing the grades of city streets with like effect as if such highway were a city street and the grade so established or changed shall be the official grade of such State highway or portion thereof.
The city may contribute any part of the expense of such proceedings, including payment of claims, out of any funds available to it for the acquisition of rights of way for the construction, improvement or maintenance of streets.
This section does not limit the right of the department, on authorization of the commission, to proceed as provided in Article 1 of Chapter 6 of this division.
Ca. Sts. and High. Code § 112