Re: Railroad Billing

Rick and PRSL offer some good examples of the myriad details.
Why? For most of the 20th Century, railroads were regulated as utilities, like a telephone company or power utility. The Interstate Commerce Commission had the power over rates and service, as well as "rate separations," the split of revenue talked about.
A "common carrier" could publish a tariff, but once it did it had to accept any loading - it could not pick and choose its customers.
(One good example: the D&RGW tried to avoid moving no. 346 from Dolores to Alamosa. A friend managed to sneak a tariff into the ICC for "dead locomotives less than 100,000 lbs. between Durango, CO and Alamosa, CO." The D&RGW was forced to accept the movement.)
Most of that went away with the Staggers (4R) act of 1979. Railroads now go after shipments like any other business. "Common Carrier" doesn't mean much any more. The ICC was eliminated.
Of course, there was a similar system in place for passenger ticket revenue . . .
JAC