A self-propelled vehicle comprises a frame and a platform pivotally mountable to a rear portion of the vehicle frame. The platform is pivotally movable between a first position in which the platform extends generally horizontally from the rear portion of the frame to support a rider during operation of the vehicle, and a second position in which the platform is removably secured in a generally upright position-adjacent the rear portion of the frame to enable walk-behind operation of the vehicle.