Are there culverts on your layouts?
Railroads actually prefer culverts over bridges because they require less maintenance and are not as prone to destruction as trestles and bridges.
I’m building a whole series of culverts on mine.
On NS
this one is esp. interesting on NS. The foreground culvert carries water under a spur and the background one carries water under the NS mainline in Manassas. The spur and mainline come together a short ways off to the right of this picture.
the good ole RF&P (CSX) decided in favor of a series of culverts for this particular Potomac River tributary which becomes a raging river during floods, instead of a bridge. We are looking from a northbound VRE train on NS tracks, which are about to join CSX in Alexandria (or Springfield?)
here’s a wider view of same