Scenery Detail #2: Road Bridge
Adding scenery detail, like a road bridge add interest and also heigh to a model railroad. They are also good for providing scene dividers.
A nice example is the image below:
The above image shows the very good modeling of a busy and well-used road. If you look at just the road nearest the camera it could be the prototype. In the real world, this road needs repairing and probably widening to accommodate a larger amount of traffic.