I have a few hypothetical questions here, let’s set up the scenario. Lets say I owned an 18 mile branch serving 5 industries, shipping in total about 15 cars a week.
How do you decide how much to charge the customer?
Your hypothetical scenario reminds me of an actual branch line of the MoPac (formerly T&P) which ran some 20 miles from Shreveport to Hosston, LA. The branch at one time had some agricultural customers but at its end served only a small refinery at its Hosston end point. The refinery shipped some 12 tank cars per week and the MoPac ran a train two days a week each carrying about 6 empties to the refinery and returning with 6 loads.
The railroad had some contractural obligation to provide service as long as the refinery shipped some number of cars each month. Apparently the refinery owners forgot the details of this agreement and they shut down for maintenance and IIRC some plant upgrades which took more than a month to complete during which time they didn’t call for any rail service. On the 31st day the MoPac sent in a crew and started tearing up the rails from the end of track at the refinery and working back to the branch’s connection in Shreveport. The refinery owners squealed like stuck pigs but that didn’t faze the MoPac which was delighted to be rid of this unprofitable line. That was about 20 years ago and the refinery started up after their shutdown but operated for only a short time after losing their rail service.