Portland is a city of bridges, and each bridge has its own story. The Steel Bridge has the distinction of being the only double-decker bridge in the world with independent lifts and was opened in 1912, spanning the Willamette River connecting Northwest and Northeast Portland. It carries not only car traffic but also pedestrians, bicycles, light rail, and trains. It was originally built to replace an 1888 bridge which had the same name.
Both of the decks of the bridge can rise independently of one another, although at times both must rise to allow larger boats to pass underneath the bridge. With the railroad on the lower deck, however, it's possible to lift the lower deck for smaller boats without disturbing the car traffic on the upper deck.
The Steel Bridge is near Union Station in the Old Town Chinatown neighborhood. It's at the northern end of Tom McCall Waterfront Park, making it a popular crossing point for walkers and cyclists who are making a circuit of the walkways on both sides of the river.