Overall, kudos to you just for using such a small scale but fdor getting a good feel for the size of you subject.
I'd consider havingthe turret of the AAV on the overpass facing up the road, as though in overwatch for the track passing underneath.
The bridge looks pretty good, though a bit untouched, generally there are bullt marks on most concrete surfaces here.
The earth along the roadside is strewn with trash here, as well as with weedy plants, and the rtemains oif guardrails.
Overall, I really like what you are trying to portray, and I can't imagine working in such a small scale.