Cal. Sts. & Hy. Code § 100.2
The department is authorized to enter into an agreement with the city council or board of supervisors having jurisdiction over the street or highway and, as may be provided in such agreement, to close any city street or county highway at or near the point of its interception with any freeway or to make provision for carrying such city street or county highway over or under or to a connection with the freeway and may do any and all work on such city street or county highway as is necessary therefor. No city street or county highway shall be closed, either directly or indirectly, by the construction of a freeway except pursuant to such an agreement or while temporarily necessary during construction operations. No city street, county road, or other public highway of any kind shall be opened into or connected with any freeway unless and until the commission adopts a resolution consenting thereto and fixing the terms and conditions on which such connection shall be made and the commission may give or withhold its consent or fix such terms and conditions as, in its opinion, will best subserve the public interest.
Ca. Sts. and High. Code § 100.2