Jeff,
You need to create a session in order to drive your trains.
1) Create a session in the Session menu off the routes screen by clicking on a route (yours) and then choosing Sessions on the right.
2) Once your session is created, place your trains where you want them.
Now we assign drivers...
Open up the Driver setup which is located at the top of the Surveyor screen. Yes, both Surveyor - route editing and Session editing look the same... This is a white icon that looks like a piece of paper.
1) Click on driver setup and add or remove drivers. I usually place a bunch of consists then remove any pre-assigned drivers then add in what I want including some unassigned ones so I can have them do other things...
2) Once you have your drivers assigned, you then add their driver commands to the queues one at a time...
3) Using Navigate To and Drive To commands, you can then setup the path for the driver to move on. You choose these by clicking on the little >> arrows on the list.
Track marks are used to guide the drivers on proper tracks and to lead them in a particular direction. You can have them navigate via which makes them go past the track mark, our have them navigate to which means they will stop at. If you put a navigate to with commands that follow, it works almost like a navigate via. The process is pretty straight forward for adding commands. You have to explore the route and get to know where things are. Stations and industries require two parts... You need to 1) Drive or Navigate to these, then 2) Choose the function such as load, unload, or whatever is necessary. With passenger stations, it's a 3-part process because you also need to choose the platform from the little pull-out, and also put in the function such as load. The load command actually triggers the stations or industry to do their part. With passenger trains, the train will slow down and stop then the doors will open. With industries they will load the goods..., or if you are delivering, you use an unload command to unload the goods such as steel, wood, or coal...
Once all your drivers have assigned routes, save your session and drive it. This will become a troubleshooting/fixing cycle for some time until you work out the little quirks that have gone unnoticed whether this is a route-related bug, or a session-related one like choosing the wrong track mark, for example.
Remember any changes you make in a session won't be reflected on the route. So if you notice something like floating roads in an area, edit the route in Surveyor, where you built the route, and then go back and drive. It's also important to note that if you save a session while in driver, any changes you make to the route or session, such as fixing something, will not be reflected in the saved driver session.
Hope this helps.
John