Well since the railroad ties are made of wood, and they are the only thing that could even be considered a deck on this railroad bridge, then the deck is therefore wooden.
Iowa Interstate RR Green River Bridge
Posted March 15, 2012, by Steve Conro (sconro [at] yahoo [dot] com)
I think I might argue that abandoned railroad ties don't count as a wooden deck.
Well since the railroad ties are made of wood, and they are the only thing that could even be considered a deck on this railroad bridge, then the deck is therefore wooden.