They are also used in electric vehicles , such as electric milk floats , elevators , and conveyors . Vehicles with electrical transmission systems such as Diesel-electric locomotives , electric hybrid vehicles and battery powered electric vehicles . Traction motors are used in electrically powered rail vehicles such as electric multiple units and electric locomotives , other electric vehicles such as electric milk floats , elevators and conveyors as well as vehicles with electrical transmission systems such as diesel-electric , electric hybrid vehicles and battery electric vehicles .