A patient transport apparatus comprises a support structure comprising a base and a patient support surface for supporting a patient and a caster assembly coupled to the base. The caster assembly comprises a wheel assembly. The wheel assembly includes a first edge, a second edge, and a center disposed between the first edge and the second edge. Each of the edges have a lower coefficient of friction than the center. The caster assembly further includes a tilt assembly coupled to the wheel assembly. The tilt assembly is configured to allow the wheel assembly to tilt relative to a floor surface such that at least one of the first and second edges contact the floor surface.
