Is it legal for all the trucking companies in the United States to organise for a fuel surcharge?

If all the trucking companies imposed a fuel surcharge of one dollar per loaded mile, to be given to the person that pays for the fuel at the pump and for every truckload to be no less than two dollars per loaded mile. Would the shippers and brokers of this country have to honor their rates or is it illegal for that industry to charge a minimun rate for their services?