Abstract: A traction device for a wheeled vehicle comprises a rotor mounted to a supported component of the vehicle and displaceable between a deployed position, in which the rotor is close to the ground and in contact with the tire of a driven wheel of the vehicle so that when the tire rotates, the rotor rotates through frictional engagement therewith, and a stowed position, in which the rotor is farther from the ground and is spaced from the wheel. At least one elongate traction element is attached to the rotor at a location spaced from the axis of rotation of the rotor, so that when the rotor rotates due to frictional engagement with the rotating tire, the traction element is subject to centrifugal force and is extended from the rotor and passes between the tire and the ground.