Final answer:
Excessive wear on the edges of the tires indicates under inflated tires, because the lack of pressure causes the tire's edges to bear more of the vehicle's weight.
Step-by-step explanation:
Under inflated tires are indicated by excessive wear on the edges of the tires. This is because when a tire is under inflated, the lack of pressure means that the tire's edges make more contact with the road than the center, leading to excessive wear on those edges. When tires are properly inflated, they maintain an optimal shape that distributes the weight of the vehicle evenly across the tire's surface, minimizing wear. If the tires wear excessively in the center, this is typically a sign of over inflation, with too much pressure causing the middle part of the tire to bulge and make more contact with the road.