eg. Tsing Ma Bridge and Kap Shui Mun Bridge in Hong Kong have six lanes on their upper decks, and on their lower decks there are two lanes and a pair of tracks for MTR metro trains.
Windmill Lane, Southall, Middlesex is the site of the "Three Bridges Ancient Monument" created by Brunel. Here the road goes over the Grand Union Canal and the Great Western Railway goes underneath both at the same spot. So not quite the same as your question but close!