Said agreement or agreements shall provide that the cost and expense of constructing, reconstructing, or maintaining said bridges shall be borne as follows: as to the bridges proper, fifty (50) per centum by the Commonwealth of Pennsylvania and fifty (50) per centum by the State of New York; as to construction, reconstruction or maintenance of bridge approaches in Pennsylvania, the costs thereof shall be paid entirely by the Commonwealth of Pennsylvania; if the bridge approach is in New York, the Commonwealth shall have no liability for payment of construction, reconstruction or maintenance costs thereof.
36 P.S. § 3535