[Swisher]

Good luck getting your goods without them. What would happen if we split all the heavy trucks into several smaller trucks? That would make the problem worse. Besides the primary importance of the highway system is to transport goods and necessary resources to areas not accessible (or not economically practical) by rail/sea.

[scarmig]

Actually, splitting the heavy trucks into smaller trucks would be better, paradoxically. Wear and tear on the road increases exponentially with vehicle weight. Weigh stations account for this by increasing the cost per pound for larger weight classes of truck.

The reason it doesn't happen is because then you've got to pay additional drivers, which outweighs the cost savings from avoiding the additional road use taxes.