California Code, Vehicle Code - VEH § 35788

Upon application to the Director of Transportation for permission to use and operate on highways private or contract vehicles for the purpose of hauling loads which weigh in excess of the maximum load weight limits, the director may enter into an agreement with the applicant, permitting such overloads, specifying protective restrictions and providing for the payment of a financial contribution for the issuance of such permission, except that the overload shall not exceed 25 percent of the maximum load weight limitation, in pounds, set forth in this code.  The agreement shall not permit the applicant to transport such excess weight loads on highways for distances exceeding 75 miles.  All contributions received by the Department of Transportation shall be used for the construction, improvement, or maintenance of the highway designated in the permission to operate overweight loads.  Sections 188 and 188.8 of the Streets and Highways Code does not apply to contributions received pursuant to this section, and any expenditures of the contributions by the department shall not be credited against amounts required to be expended pursuant to Sections 188 and 188.8 of the Streets and Highways Code.

This section does not apply to highways which are a part of the National System of Interstate and Defense Highways.