Bridges Around The World

Some bridges are not fixed crossings, but can move out of the way of boats or other kinds of traffic which, ideally, moves under them, but is sometimes too tall to fit. These are generally electrically powered.
Double-decked bridges
Double-decked or double-decker bridges have two levels, such as the San Francisco – Oakland Bay Bridge, with two road levels. 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. Likewise, in Toronto, the Prince Edward Viaduct has four lanes of motor traffic on its upper deck and a pair of tracks for the Bloor–Danforth subway line. Some double-decker bridges only use one level for street traffic; the Washington Avenue Bridge in Minneapolis reserves its lower level for automobile traffic and its upper level for pedestrian and bicycle traffic (predominantly students at the University of Minnesota).