Abstract: A multiple axle trailer is disclosed consisting of a main chassis articulated to a tractor unit and a sub-chassis relative to which the main chassis rotates on a turntable. The sub-chassis has a pair of forward wheel (3) and pair of rear wheels (4), each of which rotates on a stub axle and king pin assembly (6). A steering mounting has two swinging arms depending from the main chassis, joined at their free ends by a horizontal tie. A primary link of a linkage mechanism is coupled to the horizontal tie, the linkage mechanism coupling the wheels to the steering mounting such that rotation of the main chassis relative to the sub-chassis causes the stub axles to pivot about the king pins. Movement of the swinging arms causes the line of action of the primary link to cross the axis about which the main chassis rotates relative to the sub-chassis, reversing the direction of steer for when the trailer is backed up.