Crossing small stream/river on a curve...

[pnolan48]

Oh, I forgot--

Once you start using pre- or post-tensioned concrete, bridges are often curved, and often climb or descend. Just like highway ramps, only a bit heavier. These bridges have upset the apple cart.

[nkalanaga]

The BN's Latah Creek Bridge in Spokane is also curved, with a continuous steel box girder design.  It could actually be modeled with a bent wood strips and some glued on details - if one had room for the thing.

For bridge shoes, many short spans, such as the ME 40 ft ones, didn't have "shoes" at all, only metal plates.  Those would be very easy to model.

[wm3798]

Don't be a sissy.  Scratch build a trestle!

[davefoxx]

Yeah, build a trestle!  All the cool kids are doing it.