Mixed, mostly. I have been doing mini operating sessions on my layout, I select about 7 or 8 cars that are to be delivered to various customers about the layout. I run a local using a single road switcher (GP9, RS-11) to deliver and pick up cars from the various customers. I also have a second line that I interchange cars with. As the second line interchanges and crosses the main line several times, I have to keep on my toes when having an operating session. A typical session last about 2 hours. If I want to just let the trains run without a specific purpose I will sometimes run a unit grain train, coal train or a train of gondolas with pipe loads. These trains are usually pulled by several high horsepower units MU'd. I just turn them loose and let them roam the layout.
I guess it all depends upon how much mental effort I want to put into running my trains on any given day.
Tom
