A tire includes, among the conventional tread pattern elements, at least
one measuring element having a central zone and an encircling zone. In
normal operation, the central zone 10 of a measuring element slides over
the ground while, conversely, the tread as a whole does not slide over
the ground. Measurements are carried out of the maximum adherence
potential with the ground, at any moment, due to the central zone of a
measuring element. In an alternative embodiment, the measuring element
may comprise a circumferentially extending rib(s) or tread block(s) whose
ground contact surface(s) is spaced at a lesser radial distance from the
wheel axle than the spacing of the ground contact surfaces of the
conventional tread blocks.