The passage of public law 533 enabled construction of a bridge between Bettendorf, Iowa and Moline, Illinois. Partnership of Modjeski, Masters, and Case was chosen to lead the design and construction of the new bridge.
Construction of the original bridge begins in June 1934. The structure would feature a main suspended span of 740 feet and a total length of over 5,000 feet.
Construction of the original bridge was completed and opened to traffic on November 18th, 1935.
Modjeski and Masters was tasked to study increased traffic volumes and make recommendations for expanding the facility. It was decided that another suspension bridge would be needed.
Construction of the twin suspension bridge starts in July 1958. It was designed to be as close to the original bridge but with a wider deck to accommodate increased traffic loads.
Construction of the new bridge was completed in 1959 and was dedicated on January 20, 1960. The older bridge was designated to carry Northbound traffic while the new bridge would carry Southbound traffic.
Starting in 2008. Modjeski and Masters, as part of the Alfred Benesch design team, was tasked with providing final design services for the new I-74 Mississippi River Bridge. Located on a new alignment to the east, this will be no ordinary crossing. The new I-74 Mississippi River Bridge will feature dual basket-handle arch bridges with main channel spans of 800 feet. The bridges support six design lanes in each direction, including an outboard bicycle and pedestrian path.
Construction on two river-crossing arches starts in 2017 and is expected to take four years. Removal of the existing Iowa-Illinois Memorial Bridge will follow.
Construction on two river-crossing arches was completed in December 2021. Removal of the existing Iowa-Illinois Memorial Bridge is expected in 2022.