Indiana Code Title 8. Utilities and Transportation § 8-8-3-3

Sec. 3. The Indiana department of transportation may require locomotive engines to be so constructed that the engineer and fireman's view ahead from the front cab windows is clear and unobstructed by any part of the engine, equipment, or appliances used or operated, and constructed that the cab deck shall be of the same height, and shall give the fireman and engineer operating the locomotive engine an even surface to stand and work upon, and constructed that the switch engines have the tank and tender built so that the engineer and fireman operating and controlling the locomotive engine can have a clear view along the track, both front and rear, without the view being obstructed by part of the engine, tank, or tender.