They did, the rebating prohibition was mostly to stop a carrier from offering favorable shipping rates to one shipper while charging higher rates to another. Th

They did, the rebating prohibition was mostly to stop a carrier from offering favorable shipping rates to one shipper while charging higher rates to another. The ICC methodology was helpful in stopping the roads from abusing shippers, however the ICC regulated the Railroads as if they were the only kind of transportation available, so when the rail industry wanted to lower rates, or reduce service once trucking appeared, they were denied the ability to respond to market conditions. The ICC was also known for its turgid yet protracted decision making process - the Union Pacific, Rock Island Merger case is a great example, the decision making process took so long that the RI basically was bankrupt by the time it was approved, at which point the UP no longer wanted a bankrupt (and 20 years maintenance deferred) road. In addition to that one of the prime forces that led to the NYC/PRR merger, and later bankruptcy, was that because of the ICC price setting mechanism, and other changes to the trackside industries that they served, they were effectively regulated into bankruptcy (there are other contributing factors too, like usurious property tax rates in their operating areas, and inflexible outdated work rules, for example, that required three man crews on diesel locomotives). I don't mean to say that regulation is bad, but one should be careful how that regulation is crafted, and the regulation must be updated from time to time - the underlying methodology must be regularly renewed to ensure they are not girdling the businesses being regulated. That said, the regulatory model used by the ICC and CAB (Trains/Trucks/Busses and Airplanes Respectively) was beneficial early on, but failed to adapt to changing market conditions. Quite Arguably the Staggers Act (Railroad), the Motor Carrier Act of 1980 (Trucks and Busses) Airline Deregulation Act of 1978 (Airlines), left their regulated industries healthier and more competitive than before, and adjusted for inflation, rates for all of these industries are lower now than they ever had been, and all three are (generally) more profitable, while still providing lots of high paying decent jobs for folks.