36 Pa. Stat. § 3401.12
The Delaware River Joint Toll Bridge Commission, in the exercise of its authority to make and enter into contracts and agreements necessary or incidental to the performance of its duties and the execution of its powers, shall adopt standing operating rules and procedures requiring that, except as hereinafter provided, no contract on behalf of the commission shall be entered into for the doing of any work or for the hiring of equipment or vehicles where the sum to be expended exceeds $10,000 unless the commission shall first publicly advertise for bids therefor, and requiring that the commission award the contract to the lowest responsible bidder; provided, however, that such advertising shall not be required where the contract to be entered into is one for the furnishing or performing services of a professional nature or for the supplying of any product or the rendering of any service by a public utility subject to the jurisdiction of the Pennsylvania Public Utility Commission or the Board of Regulatory Commissioners of New Jersey and tariffs and schedules of the charges made, charged or exacted by the public utility for any such products to be supplied or services to be rendered are filed with the appropriate boards.
36 P.S. § 3401.12