A control car, control trailer or driving trailer is a generic term for a non-powered railroad (US) or railway (UIC) vehicle that can control operation of a train from the end opposite to the position of the locomotive. They can be used with Diesel or electric motive power, allowing push-pull operation without the use of an additional locomotive. They can also be used with a power car or a railcar. In a few cases control cars were used with steam locomotives, especially in Germany and France (see article Voiture État à 2 étages).