California Code, Vehicle Code - VEH § 22404

The Department ofTransportation or local authority making a determination of the maximum safe speed upon a bridge, elevated structure, tube, or tunnel shall first make an engineering investigation and shall hold a public hearing.

Notice of the time and place of the public hearing shall be posted upon the bridge, elevated structure, tube, or tunnel at least five days before the date fixed for the hearing. Upon the basis of the investigation and all evidence presented at the hearing,the department or local authority shall determine by order in writing the maximum speed which can be maintained with safety to the bridge, elevated structure, tube or tunnel. Thereupon, the authority having jurisdiction over the bridge, elevated structure, tube, or tunnel shall erect and maintain suitable signs specifying the maximum speed so determined at a distance of not more than 500 feet from each end of the bridge, elevated structure, tube, tunnel, or any approach thereto.