An image forming apparatus includes an image forming unit, a first main body frame and a second main body frame, a sheet placing portion, a feed roller, a link arm and a bridge frame. The split circumference wheel assembly includes separable inboard and outboard support walls that are spaced axially apart a maximized distance so that the motor driver assembly is completely contained within the maximized space defined. Upon detecting the event, EW code performs an early action warning, or issues an early action. The plate 57 is unrotatable and axially movable with respect to the front cover 2, and is arranged on the turbine side of the plate 52. If it is judged that the front road-shape is not covered by the first illumination range beforehand, the second control circuit controls the actuator to cover the road-shape by the second illumination range. The ratio of the driver input control angle to the steering angle defines a steering ratio.