Land grants represent less than 10% of the total rail miles constructed, and land grants were given so the railroads could finance the construction and operation of the railroads without further government intervention. Land grant railroads were required to move government goods mostly for free, but at times some lines got to charge a minimal rate, and railroads were required to pay property taxes on all the granted land---including the worthless land. According to the Washington Department of Transportation, 18-wheel trucks loaded to 80,000 gvw are equal to 9250 full size cars (ie Lincoln Town car, F-150 size) worth of wear and tear on the road surface. Truckers don't pay anywhere near that amount in fees and taxes, and the ATA argues that paying any more than 10% of that amount is unfair.