Because all the sessions I create are an attempt to be as prototypical as possible, all my sessions are CMTM based, (which should come as no surprise). Like John, I drive the route to explore and get familiar with the trackage, towns, industries and portals. Then I make a list of all the industries and portals, and place a track mark at every location where a car will be delivered, including at least one empty car storage (ECS) track on the route.
If the route has interactive indusries, I make sure they are all turned off. Then I analyze each industry, deciding how many carloads of what commodities it will consume or create in a seven day period. Then I decide where the inbound commodities will originate and to where the outbound commodities are destined. One of my choices in each of these decisions is "random". This is my industry analysis data.
I have created an Excel worksheet that helps me create the CMTM movement records from this information. First I enter the industry, portal and ECS names. Then all the commodity names (including kuid numbers). My worksheet is already populated with the various car types that is represented in the cars config file as the Category Class.
Then I enter the industry analysis data and with the click of an onscreen button, all the CMTM records that reflect the car movements to and from industries are created.
The click of another on screen button prints out reports for each Portal and ECS track for each day. These reports help in making up the consists that will arrive on the route via portals.
Once I have all the CMTM work done, then I define what trains will run and when. If I am creating an actual railroad that has published timetables available, I will usually follow them. If it is a fantasy route, then I make up a list of trains that I think would be fun to have running and from that, create a timetable using a string diagram. I even include 'extras" in the string diagram, to make sure there is a hole in the traffic that will accommodate the movement required.
Next, I create the consists that will be emitted from the portals. Then I place cars and consists that will be on the route at start-up. At this point, I go back and add the CMTM records that are required for the "on route" cars and consists.
As this process is underway and I have defined the movements of a specific train, I will place any track marks that are necessary for it to navigate. Then I will test to make sure all works well.
I choose to make most of my player operations working the yards and delivering cars to industries. My through freights are usually programmed with Driver Commands to drop-off and/or pick up cars at various locations on the route.
The largest route I have done to date from a traffic pespective is the SOO line Schiller Park Yard. it starts out on Monday with 720 inbound cars on 18 different trains. It gets busier each passing day.
David