The maximum axle load shall not exceed the number of pounds designated in the following provisions which prescribe the distance between axles:
A.
When the axle spacing is nine feet or more between axles, the maximum axle load shall not exceed 18,000 pounds for vehicles equipped with high pressure pneumatic or balloon tires.
B.
When the axle spacing is less than nine feet between two axles but more than 3 1/2 feet, the maximum axle load shall not exceed 13,000 pounds for vehicles equipped with high pressure pneumatic or balloon tires.
C.
When axles are spaced less than 3 1/2 feet apart, the maximum axle load shall not exceed 9,000 pounds per axle.