Ohio Rev. Code § 4907.41: Supply of cars.

Upon reasonable notice, each railroad shall furnish suitable cars for all persons who may apply therefor, for the transportation of any and all kinds of freight in carload lots, if it is within its power to do so. In case of insufficiency of cars at any time to meet all requirements, such cars as are available shall be distributed among the applicants therefor in proportion to their respective immediate requirements, without discrimination between shippers, or between competitive or noncompetitive places. Preference may be given to shipments of livestock and perishable property.

The public utilities commission may enforce reasonable regulations for furnishing cars to shippers, switching, loading, and unloading cars, and the weighing of cars and freight offered for shipment over any railroad.