Construction has started on Interstate 270 to replace the Chain of Rocks Bridge over the Mississippi River with twin bridges to help improve freight transportation.
“This isn’t just an investment for the Metro East region — it’s an investment for our entire nation. This major freight corridor connects our ports and railways — essential to maintaining a steady supply chain for Illinoisans, Missourians and all Americans alike,” Illinois Gov. J.B. Pritzker said at an event launching the project.
Built in 1966, the existing bridge over the river is two lanes in each direction with narrow, one-foot shoulders that pose safety concerns for vehicle breakdowns and first responders. The bridge accommodates 51,000 vehicles a day, about 20% of which are trucks, and the structure requires frequent maintenance and repairs due to its age.
The $496.2 million joint IDOT-MoDOT project will replace the bridge with two structures that have wider shoulders that can accommodate the eventual expansion of I-270 to three lanes in each direction. A companion $35.4 million Missouri Department of Transportation project will reconstruct the Riverview Drive interchange just west of the bridge.
“The I-270 Chain of Rocks bridge represents the great partnership between Missouri and Illinois investing in this vital freight corridor connecting I-270 to I-70,” said Missouri Gov. Mike Parson. “Along with the bridge, Missouri is transforming I-270 as well as making historic improvements to I-70 across the entire state.
Infrastructure has remained a top priority for us since the very beginning. We’ve come a long way in Missouri, and as witnessed with this project and countless others, we are not done yet.”
Construction started last winter and is anticipated to wrap up in 2026. Additional information can be found by visiting the project website at www.270mrb.com.
“It’s incredibly important we maintain and improve our state’s infrastructure. The Chain of Rocks Bridge plays a critical role in connecting those coming to and from the Metro East and Greater St. Louis Area,”said Senator Erica Harriss (R-Glen Carbon). “As traffic counts have more than doubled since the construction of the current bridges, there is a critical need to replace the bridges and improve the overall safety for both passenger and commercial traffic.”
Missouri and Illinois continue to coordinate on long-term plans to add a third lane in each direction on the I-270 bextending as far east as Illinois 157. In IDOT’s current multiyear improvement program, $75 million is identified courtesy of Rebuild Illinois for an additional lane between the river and just east of St. Thomas Road, a project that includes the reconstruction of the Illinois 3 interchange.
Rebuild Illinois (RBI) is committing $33.2 billion over six years into the state’s aging transportation system, creating jobs and promoting economic growth. RBI is not only the largest capital program in state history, but also the first that touches all modes of transportation: roads and bridges, transit, waterways, freight and passenger rail, aviation, and bicycle and pedestrian accommodations.