As the Portland Mall has trains running clockwise along
the two main streets, it is
necessary for LRVs to and from Steel Bridge to cross over the rails carrying
traffic in the opposite direction.
This image shows some of that complex trackwork near Union Station.
red lights to the left govern freight and Amtrak, which utilize the lower level
of Steel Bridge, ahead and out of view to the left, to head for points south
and east along Union Pacific rails.