Lloyd , first off , a beautiful layout !! It would make sense to me to have a couple of spurs for storage , either empty boxes or hoppers. As it looks to me now each track is an active track . I don't see a place for car storage once a car is unloaded and in certain cases , full cars depending on what they are carrying . The industry is large enough that I would think you almost have to treat it as a small switching yard . The run around will help to give you some switching opportunities but you cant have that little SW-9 loafing all day .