JTG: As the industrial buildings are the dominant "topography", your reasoning makes perfect sense.
The same goes for the Columbia Gorge, in the area I'm from. If I modeled the SP&S/BN/BNSF, east would be to the right, with the river in the foreground, and the mountains in the rear. But if I modeled the UP, east would be on the left, for the same reasons. If I had lots of room, in a long, skinny space, I'd model both sides, with the river as the aisle, connecting the two sides at Portland, the Tri-Cities, and Wishram.