Re: Kingan packing
Please do not rule out that the car in question could be carrying drugs, printers ink, magazines, etc.
Look at this list in the files: https://realstmfc.groups.io/g/main/files/Perishable%20Commodities,%20definition%20and%20list%20of I uploaded some time ago.
And note on the scanned page eleven, the key for commodities that need to be protected from both heat and cold. It is only three years distant from your date, and closer to your modeled time than me, however should be applicable.
I wondered years ago about if I had too many reefers, and I still think I do. However after researching and then presenting on what I had found years ago on reefer travels, and finding the above data and much, much, more, I came to the conclusion that it was not as severe as I thought it was and by swapping out cars, it could be both, dealt with with different cars rotated through, and thereby some freshness introduced by not having the same cars rotate through yards and so on.
As you are also modeling a through route (IIRC from your excellent CCB presentation many years ago,) you do need some through traffic as do I. The cheapest through traffic cars in real $$ are the ones you own now. Jim Dick - Roseville, MN