For what it's worth, I currently have 23 freight cars on the layout, and 18 industry locations to move them among. 16-20 revenue cars are moved each day (the others have a "Hold for 1 Day" or "Hold for 2 days" notation on the car card for their current location.) I have a "6 car maximum" rule for all movements on the main or while switching (including a mandatory caboose or combine when running between towns), and a "5 car maximum" rule for all movements on the Prospect Harbor branch. I've learned that moving 16-20 cars in short trains to their new destinations requires four scheduled out-back trains from Winter Habor per day (3 to Goodwin and 1 to Prospect Harbor.) Every several days, I need to run an afternoon "extra" to handle heavier than usual traffic -- i.e. fewer cars with "Hold" orders. It generally takes me about 2.5 hours of real time to complete a full daily cycle, but of course I can stop operating at any time and continue later. I've probably run 30 simulated days to date, both alone and with an occasional second operator, and my car card system continues giving me fresh challenges and new train consists every day. The reason for this is that some of my cars take as little as 2 days to cycle (2 ventilated boxcars of fresh lobsters go from Winter Harbor Seafood to the Goodwin interchange every day, have their car cards turned immediately for the return trip to WH, and then make the same run again the next day, thus taking only 2 simulated days to run through all four cycles on their car cards), while other cars cycle in anywhere from 3 to 7 days (a 7 day cycle occurs because 2 of my cars move among 4 different industry locations, with 3 days of "holds" along the way before they complete their cycles.) Adding just a few more rules adds a bit more challenge. For example, no carloads of seafood are permitted on the morning "express" run to the interchange, and that train does no way switching on the way there! In fact, ACE operating rules specify that out of respect for the noses of paying customers, loaded cars of seafood can only move from the Prospect Harbor commercial fishing dock once a day, and loaded cars of seafood headed for the interchange are permitted ONLY on the late morning "fish train" to Goodwin. Since those trains tend to be avoided by passengers if at all possible, they carry my SR&RL style long caboose instead of the line's only combine.