(f) Whenever, in the judgment of the Department of Transportation, a state highway cannot, in consideration of public safety, sustain the operation of trailers or semitrailers of the maximum kingpin to rearmost axle distances permitted under Section 35400, the director, in consultation with the Department of the California Highway Patrol, shall compile data on total traffic volume, frequency of use by vehicles covered by this subdivision, accidents involving these vehicles, and other relevant data to assess whether these vehicles are a threat to public safety and should be excluded from the highway or highway segment. The study, containing the conclusions and recommendations of the director, shall be submitted to the Secretary of the Business, Transportation and Housing Agency. Unless otherwise notified by the secretary, the director shall hold public hearings in accordance with the procedures set forth in Article 3 (commencing with Section 35650) of Chapter 5 for the purpose of determining the maximum kingpin to rear axle length, which shall be not less than 38 feet, that the highway or highway segment can sustain without unreasonable threat to the safety of the public. Upon the basis of the findings, the Director of Transportation shall declare in writing the maximum kingpin to rear axle lengths which can be maintained with safety upon the highway. Following the declaration of maximum lengths as provided by this subdivision, the Department of Transportation shall erect suitable signs at each end of the affected portion of the highway and at any other points that the Department of Transportation determines to be necessary to give adequate notice of the length limits. The Department of Transportation, in consultation with the Department of the California Highway Patrol, shall compile traffic volume, geometric, and other relevant data, to assess the maximum kingpin to rearmost axle distance of vehicle combinations appropriate for those state highways or portion of highways, affected by this section, that cannot safely accommodate trailers or semitrailers of the maximum kingpin to rearmost axle distances permitted under Section 35400. The department shall erect suitable signs appropriately restricting truck travel on those highways, or portions of highways.