A vehicle is provided with a chassis having a footprint, a load carrying structure, and a support assembly coupling the chassis and the structure. The support assembly is adapted to move the structure relative to the chassis between a stowed position and a deployed position outboard of the footprint of the chassis. A plurality of wheels is configured to roll on the support surface and a plurality of axles coupling the wheels to the chassis are provided. Each axle includes at least one spindle supporting an individual wheel for rotation on a spindle axis. A steering system is adapted to position the wheels between driving and rotation arrangements with respect to the chassis such that in the rotating arrangement each of the plurality of wheels rotate relative to the chassis whereby the chassis, the platform and the support assembly may rotate in unison about the steer axis.