Abstract: A vehicle tire with traction-improving devices, wherein the basic tire has a plurality of uniformly spaced apart cross grooves running essentially from sidewall to sidewall. Each groove is fitted with an inflatable bag or bladder which, when uninflated, retracts within the circle of the road-engaging surface of the tread. An annular manifold is affixed to at least one sidewall and is connected by conduits to the cross members. This manifold has a valved air inlet which may be used to pressurize the cross members via the manifold and thus to project the inflated members radially beyond the circle of the tread so that they engage the road surface. Depressurizing the manifold of course causes the members to retract. Each cross member is equipped with some form of traction-improving substance, structure or the like to enhance road grippability, especially in slippery road conditions.