The board of supervisors of any county may, by consent of or agreement with the proper governing authorities of any municipality within such county, assume concurrent jurisdiction over any street in such municipality for maintenance purposes where such street is a continuation of or intersects a local or county road already under the jurisdiction of such board of supervisors.
Such consent or agreement to the assumption of said concurrent jurisdiction shall be entered into only by the entering of an order on the minutes of both of said boards.
The liability heretofore imposed by law upon any municipality for or on account of the negligent construction or maintenance of any municipal street shall not be changed, diminished, or increased in any way by the provisions of this section.
Said boards of supervisors may, in their discretion, authorize the use of county-owned machinery and equipment in the construction and maintenance of municipal streets, whether or not said streets intersect a local or county road.