36 Pa. Stat. § 3141.28
In the event the Secretary of Highways determines to acquire any toll bridge by condemnation proceedings and is prevented by order of court or for any other reason from taking possession of the bridge, as herein provided, or from continuing possession once obtained, the owner or owners of such bridge shall keep and render to the Secretary of Highways an accurate account of all tolls or income collected or paid for the use, occupancy or crossing of such bridge, from and after the date and hour when the Secretary of Highways was prevented from taking possession of such bridge or from continuing possession thereof, and the amount of the tolls and revenues so collected together with lawful interest thereon, less costs of collection, shall constitute a credit against, and be deducted from, the amount which the owner or owners shall be entitled to receive for such toll bridge as finally determined in the condemnation proceedings.
36 P.S. § 3141.28