Above is a view of the highway prior to damage and erosion after gluing it up and cutting the excess foam away. Below is a view of the entire layout as it sets right now.
I've added some shell craters and damage from erosion that can be better seen in the photos below.
The bridge will actually be two spans, side by side. Each will be 24 inches long and about 8.75 inches wide with a narrow separation between them. The actual bridges are made completely from concrete castings, and are supported by six columns and a concrete beam near each end, located just outside of the sidewalks below the bridge. The truck shown in the photos is 1/50th scale.
the photo above shows erosion and decay of the concrete panels under the bridge. The erosion is in line with where the drains on the outside edges of the bridge would line up, and centered between the spans. The area of missing concrete tiles is damage located under a shell hole that will be located in the "southbound" span.
I'm hoping to finish the highway and bridge this coming weekend, maybe get the roads puttied up as well. Only making small steps, but at least it is progress. Engineering the end of the world takes time.