For dummies like me: The load on the road from one axle (2 wheels) is 10 times greater for a truck than for a car. However, the fourth power law says that the

For dummies like me: The load on the road from one axle (2 wheels) is 10 times greater for a truck than for a car. However, the fourth power law says that the stress on (damage to) the road is this ratio raised to the fourth power. The road stress ratio of truck to car is 10,000 to 1.