10 Facts You May Not Know About the I-74 Bridge
#1. The I-74 Bridge is actually the Iowa-Illinois Memorial Bridge
The I-74 bridge is officially known as the Iowa-Illinois Memorial Bridge, although it is often called the Twin Bridges or the I-74 Bridge. It was originally dedicated in November, 1935, in the memory of Iowa’s and Illinois’ World War 1 Veterans. When the second span of the bridge was built (1959), the bridge was rededicated to local veterans of both World Wars. The Iowa-Illinois Memorial Bridge was finally dedicated to include local area veterans from the World Wars and those who served in the Korean and Vietnam Wars when it was opened to Interstate 74 traffic (1970s).
#2. The I-74 Bridge is a Pair of Suspension Bridges
The Twin Bridges are actually a pair of suspension style bridges that carry Interstate 74 across the Mississippi River and connect Bettendorf, Iowa, and Moline, Illinois. These bridges display classic details that are shared with many of the suspension bridges associated with their designer and engineer, Ralph Modjeski, who also designed the Delaware River Bridge (later renamed to the Ben Franklin Bridge).
#3. Ralph Modjeski designed the I-74 Bridge
The Iowa-Illinois Memorial Bridge was designed by the engineer, Ralph Modjeski, who was born in Poland in 1861. His first commission was in 1893 when he designed a bridge that would combine a railroad and highway bridge. This bridge is also in the Quad Cities area (The Government Bridge) in Rock Island, Illinois. His last project was the design of the second span of the Iowa-Illinois Memorial Bridge. So Modjeski started and ended his career in the Quad Cities area.
#4. The I-74 Bridge Began as a Toll Bridge
The first span of the I-74 Bridge opened as a toll bridge in 1935. Traffic studies indicated that creating a toll bridge between Moline, Illinois, and Bettendorf, Iowa would effectively pay for itself. The tolls remained in place until the bridge came into the Interstate System in the 1970’s. The last toll was taken on December 31, 1969. The toll rates were 15 cents for cars, 5 cents for pedestrians, and trucks varied based on size and weight.
#5. The I-74 Bridge has a Capacity of 48,000 Vehicles
The Iowa-Illinois Memorial Bridge was built for a daily crossing of 48,000 vehicles. While the daily average is 80,000 vehicles according to a letter sent to the Governor of Illinois, Bruce Rauner, in December of 2015 by Cheri Bustos, a Congress Member for the 17th District of Illinois.
#6. The I-74 Bridge was one of the Public Works Administration’s Projects in the Quad Cities during the Great Depression
The I-74 Bridge was original funded by the Public Works Administration (PWA). The PWA was created and directed by Harold L. Ickes under the National Industrial Recovery Act of 1933. The goal of this project was to focus on major infrastructure and other large-scale projects, such as building dams, bridges, irrigation systems, in order to stimulate the economy and provide permanent improvements for the United States’ Citizens. The first span of the I-74 Bridge cost $1.45 million, which was paid back to the US government through the tolls that were collected.
#7. The Twin Bridges are Almost Identical
Despite the two spans of the Iowa-Illinois Memorial Bridge being built at different times (1935 and 1959), the two spans are virtually identical. Modjeski’s original design plans for the first span were used, with slight modifications, when the second span needed built to accommodate the increased traffic.
#8. The I-74 Bridge had to Undergo Significant Changes to Join with the Interstate
When the Twin Bridges were brought into the Interstate in the 1970’s, a number of changes had to be made to the original designs so that it fit current Interstate standards. Some of these changes were the removal of sidewalks, replacement of railings that had been along the sidewalks, removable of the tollbooth, construction of new on-and-off ramps on both sides of the river, and no longer allowing pedestrians across the bridge.
#9. The I-74 Bridge was the Third Way Across the Mississippi River in the Quad Cities
Before 1935, when the first span of the Iowa-Illinois Memorial Bridge was built, the only way to travel between Moline, Illinois and Bettendorf, Iowa was by ferry or (after 1896) by crossing the Government Bridge between Rock Island, Illinois, and Davenport, Iowa.
#10. The I-74 Quickly Became an Iconic Landmark
The Twin Bridges quickly became an icon for the Quad Cities after their construction. Images of the bridges immediately appeared in local business advertising, as well as on Quad Cities postcards. The Twin Bridges continues to be an iconic landmark of the Quad Cities area even today!