IDOT wants to know what you think about replacing Chain of Rocks Bridge

Illinois Department of Transportation is nearing the end of its two-year engineering study on proposed construction of a new Chain of Rocks Bridge and is giving area residents a final chance to weigh in before the design phase.

An open-house-style meeting is from 4 to 7 p.m. Jan. 17 on the Granite City campus of Southwestern Illinois College. Officials will show exhibits, answer questions, hear verbal comments and accept written comments, as they did during meetings last summer.

“(The bridge is) performing fine for now, and we do inspections on it,” said Kirk Brown, program development engineer for IDOT District 8, based in Collinsville. “But because of the age, we know it’s time for it to be replaced.”

Built in 1966, the four-lane bridge carries Interstate 270 traffic across the Mississippi River from Madison County to north St. Louis. Officials say it wasn’t designed to accommodate an average 51,000 vehicles a day (up from 19,800 in 1975). Maintenance costs are rising, and there are safety concerns.

“It doesn’t have wide shoulders,” Brown said. “If you have a car accident or if your vehicle breaks down, there’s no place to pull over.”

The bridge is jointly owned by Missouri and Illinois, which share maintenance costs, but IDOT is the lead agency. The states have paid for the engineering study and design of a new bridge, but not construction, so it could be years before a final decision. IDOT’s “working number” is $200 million, Brown said.

Officials envision a design similar to the current 5,400-foot-long bridge, focusing on functionality, with concrete piers and steel beams supporting a concrete deck that could accommodate up to six lanes. The new bridge would be built slightly north, slightly south or in roughly the same location as the current bridge.

“It would not look too unlike what you see today,” Brown said, adding that there are no plans to make it a “marquee” structure like the new cable-stayed Stan Musial Veterans Memorial Bridge in downtown St. Louis.

Chain of Rocks Bridge designers don’t have to accommodate Mississippi River traffic because barges and other boats are diverted through the Chain of Rocks Canal at that location.

The new bridge project is supported by East-West Gateway Council of Governments, a cooperative of elected officials in Missouri and Illinois with staff that helps coordinate projects involving federal, state and local agencies.

“The problem is always finding the money,” said Director of Transportation Jerry Blair, noting both states would have to make the project a priority despite budget constraints. “... It’s going to be a challenge to get there, but I’m not saying its impossible.”

Blair said the current four-lane bridge could become a “bottleneck,” given that IDOT and Missouri Department of Transportation already have widened or are preparing to widen other portions of Interstate 270 to six lanes.

Blair noted that Interstate 270 is a major freight-hauling route in St. Louis. IDOT data shows that 17 percent of bridge traffic involves trucks.

“We anticipate a pretty significant increase in freight traffic in the future,” Blair said. “There’s a lot more dependence on trucks because of changes in the economy, manufacturing and the way distribution works. There’s more of a need for almost instant delivery.”

A new bridge is high on a list of 20 projects supported by St. Louis Regional Freightway, a Bi-State Development “business enterprise” that represents and assists manufacturing, logistics and transportation companies.

“It’s one of the highest priority projects, based on input from private industry in the region,” said Executive Director Mary Lamie.

Freightway considers all Interstate 270 upgrades important for economic development because they make freight-hauling more efficient, Lamie said. The highway connects large industrial parks in Madison County, Hazelwood, Missouri, and areas around St. Louis Lambert International Airport.

“(A new bridge) will allow us to remain competitive in our regional market and the global market and create opportunities for growth and expansion,” Lamie said.

This story was originally published January 4, 2018 at 1:00 PM with the headline "IDOT wants to know what you think about replacing Chain of Rocks Bridge."