Nothing in this Act shall be construed to confer upon the Authority the right, power, or duty to order or enforce the abandonment of any present property of the railroads or the use in substitution therefor of any property acquired for the railroads in the absence of a contract duly executed by the railroads and the Authority setting forth the terms and conditions upon which relocation of the right-of-way and physical facilities of the railroads is to be accomplished. No such contract shall be or become enforceable until the provisions of the contract have been approved or authorized by the Illinois Commerce Commission.
     Any construction improvements to signaling or any other aspect of the grade separation project dictated by the Railroad or the Northeast Illinois Regional Commuter Railroad Corporation shall be paid for respectively by the Railroad or the Northeast Illinois Regional Commuter Railroad Corporation. The Railroad or the Northeast Illinois Regional Commuter Railroad Corporation, or both, shall specifically pay any and all costs associated with any upgrades to the railway.