Cal. Sts. & High. Code § 30408

If any property belonging to any county, city, public or municipal corporation, district, or political subdivision of the state is taken for the acquisition or construction of any bridge or other toll highway crossing, or the transportation facilities or additional transportation facilities thereof or thereto, or if any such property is injured or damaged by such acquisition or construction, and the payment of compensation therefor is necessary, proper, and necessary, compensation therefor as is agreed upon may be paid by the commission to the particular county, city, public or municipal corporation, district, or political subdivision of the state owning or in charge of such property, or the commission may direct that eminent domain proceedings be brought pursuant to this article for the determination of such compensation, including the determination of the interest of any such county, city, public or municipal corporation, district, or political subdivision in such property and the necessity for the payment of such compensation.