Plaintiff has appealed a summary final judgment rendered in favor of defendant. Implicit in the judgment is the holding that the trackage contract between the parties, pursuant to which plaintiff seeks a judgment for unpaid rental, was effectively cancelled by defendant as of July 1, 1967, after which date no further rentals accrued in plaintiff’s favor. The critical question involved in the action is a determination of when the trackage contract was effectively cancelled and defendant’s obligations thereunder for the payment of rent terminated. This question is one of law and is controlled by the trackage contract as modified by a ruling of the Interstate Commerce Commission imposed as a condition of the corporate merger sought by plaintiff and accepted by it. It is our conclusion that the construction placed upon the contract documents by the trial court which resulted in the holding challenged herein accords with the essential requirements of law. The judgment appealed is accordingly affirmed.