The Fort Pitt Bridge is a steel, double decker bowstring arch bridge that spans the Monongahela River near its confluence with the Allegheny River in Pittsburgh, Pennsylvania. It carries Interstate 376 between the Fort Pitt Tunnel and Downtown Pittsburgh. It was the world's first computer designed bowstring arch bridge^:00:02:43 and double-decked bowstring arch bridge. The bridge is known for its difficult lane changes, especially on the lower level, often requiring people to go from the extreme left lane across two lanes to the extreme right lane in only 300 feet.