My layout is basically a continuous loop "folded dogbone" with the tracks close enough together in the "middle" so they look like a double-track main line. They separate at each end to form return (not reversing) loops with yards in the middle of the loops. Where the two "mains" run side-by-side traffic normally is run on the "righthand" of the double main. So passenger trains especially run "westbound" on the righthand track, stop at Union Station in Denver, then curve around so when the tracks come together the trains are then running "eastbound", again on the righthand track. Continuing around and downgrade they will either stop in the yard lead at Galesburg, or continue around the loop, stopping at Galesburg station, or in some instances backing into one of the two stub-end tracks at the station. So the answer is: mainly counter- (anti-) clockwise. Likewise, freight trains that deliver coal to the electric powerplant run westbound counter-clockwise until they drop the unit cars at the powerplant "spur" (which isn't!) The spur runs downhill semi-hidden into a tunnel that comes out at the Coaltown branch, to be picked up by switchers and run back to the Galesburg yard for return uphill to the plant. Empty hoppers are pushed uphill to the powerplant siding, where they are picked up for return to the mine. Other freight trains could be run clockwise using one of three passing tracks within the return loops. I don't do a lot of "operations", and primarily run trains for my own amusement. Remember, NOT all American railroads ran "righthand". The Chicago & Northwestern ran "lefthand", especially on Chicago suburban routes. There may be others of which I'm not aware. Back in the day, there were a LOT of railroad lines.