16 Pa. Stat. § 12401
Whenever any counties shall erect any joint county bridge, or jointly acquire any toll bridge, the said counties may pay the costs of the construction and erection or acquisition of such bridge in equal proportions or in any other proportions, as the commissioners of the several counties may agree upon. Whenever it is necessary for any counties in the construction of any joint county bridge, or in joint acquisition of any toll bridge, to issue bonds in payment of such construction, erection or acquisition, including the approaches thereto, the damages sustained by the owner or owners of lands taken in the construction thereof and including reasonable fees for necessary legal services required in such construction, erection or acquisition, the commissioners of said counties may, with the consent of the State Highway Department, if the costs of such bridge was in excess of four hundred thousand dollars, assess, supervise, and collect such tolls for the use of said bridge for all traffic as may be necessary to pay the interest on said bonds and to create a sinking fund for the payment and redemption of the same within thirty years from the date of the issue thereof and to pay also all costs and expenses of operating and maintaining such bridge between the time of the construction thereof and the date of the redemption of the last of said bonds to be redeemed by such tolls. The tolls so collected shall be distributed between such counties in proportion to the amount paid in by each county in the original construction or acquisition, and in no case shall any tolls be collected after the redemption of the original bonds issued.
16 P.S. § 12401