Perhaps the main scenic feature on the layout will be the bridge over the footpath, which still stands at the site. It is of simple construction, steel girders set into the walls either side and with support poles mid-way, a steel deck with L-section strips under the outer edges, and handrails made from steel tube.
My preferred medium is plastic, and some girder and round section plastic along with some sheet plasticard is all that is required to make this kind of structure. I used plastic rod inside the tube as a joining peg, and as seen below, to go into the ground to locate the bridge.
The handrails are made in the same way, using tube and rod section. A "jig" from a marked out piece of wood and some blu-tack helps assembly, while rods inserted in the bottom of the tubular stanchions locate in holes in the deck.
The handrails could be rather vulnerable and may be better made of soldered brass, but I prefer plastic and they seem strong enough. Once in place on the model the bridge shouldn't need handling.