By Thomas Murphy, Ph.D., P.E., S.E., M.ASCE, Todd McMeans, P.E., and Andrew Keaschall, P.E., S.E., M.ASCE, F.SEI
The area of the country known as the Quad Cities has long been a key transportation hub for national commerce: first as a port on the Mississippi River, then as a critical railroad crossing (and the site of the famous court case in which then-lawyer Abraham Lincoln defended the railroad’s right to cross the river), and finally as an integral part of the nation’s highway system in the Midwest. For the Quad Cities region — Bettendorf and Davenport in Iowa and Rock Island, Moline, and East Moline in Illinois — that integral link is Interstate 74, which has been carried across the Mississippi by two iterations of the I-74 bridge.
The first, a twin-span suspension bridge built in the 1930s (westbound to Iowa) and the 1950s (eastbound to Illinois), was a shoulderless, four-lane bridge (two lanes per span). Because the lanes were substandard in width and there were no shoulders, cars traveled right next to the stiffening trusses — an uncomfortable driving experience for some. As the Quad Cities population increased, it became evident that traffic demands would soon outgrow the bridge’s capacity and it would need to be replaced….
READ THE REST OF THE ARTICLE HERE: https://www.asce.org/publications-and-news/civil-engineering-source/civil-engineering-magazine/issues/magazine-issue/article/2022/11/new-quad-cities-bridge-improves-commuter-and-pedestrian-connectivity