 Traction grades, from highest to lowest, are AA, A, B and C. They represent the tire's ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete.The testing does not take into account cornering, hydroplaning, acceleration or stopping on a dry surface.Nor does it account for the significantly different effectiveness of ABS versus non-ABS braking systems on a tire's stopping distance.