A pushing vehicle is described for transporting at least one child, including: a wheeled chassis including a chassis frame and a plurality of wheels that are rotatably mounted relative to the chassis frame to support the chassis frame above a ground surface and which enable the chassis to be moved along the ground surface; a passenger support for supporting a child; wherein the passenger support is attachable to the frame in a mounting position by a single tool-less attachment mechanism for attaching an underside of the passenger support to the chassis frame, to support the passenger support generally above the wheeled chassis. Also described are related modular seating systems and a supporting compartment.