The I-55 Corridor Improvements project looks to finish in spring 2027, Missouri Department of Transportation (MoDOT) officials said recently.
The project includes expanding the roadway from two to three lanes in both directions from Hwy. Z in Pevely to Hwy. 67 south of Festus and many other related improvements, including numerous bridge replacements.
Project director Justin Wolf said MoDOT hopes for the project to improve safety for travelers on the roadway to conclude by the end of May.
“Yes, our goal is to have the entire project, including the new northbound bridges over Union Pacific railroad, Route Z and BNSF railroad, open to traffic before Memorial Day weekend,” Wolf said.
In March 2024, MoDOT had a groundbreaking for the construction part of the project. In addition to adding third lanes to the interstate, the project includes replacing the signalized intersection at Hwy. 67 and Hwy. CC with an interchange that allows free-flowing traffic at Hwy. 67 under a new Hwy. CC bridge; constructing of new interchanges at Hwy. Z in Pevely, McNutt Street in Herculaneum and at Hwy. 67 south of Festus; replacing 14 bridges; rehabilitating 12 bridges and other improvements.
Most of that work has been completed except for a section of I-55 in the Pevely area and at the interchange of Hwy. CC south of Festus.
The remaining project work in the Pevely area is significant, Wolf said.
“Some minor work to connect entrances along Weir Road will continue until the end of October,” he said. “Work on paving the entrance and exit ramps at the Route Z interchange is nearly complete. The challenge now is connecting the ramps to I-55 with the ongoing work over BNSF railroad (north of Route Z) and Union Pacific railroad (south of Hwy. Z). The deck for the new southbound bridge over UP railroad was poured on Oct. 16, and we are striving to pour the BNSF deck by the end of October.
“In November we will finish pouring the barrier on the bridges and the concrete approaches to the bridges. This will allow us to open the ramps to southbound I-55 and switch traffic onto the new southbound alignment in late November.”
After the southbound I-55 work at Pevely is done, MoDOT will turn its attention to northbound work in the Pevely area, including similar intersection improvement work on the northbound I-55 exit at Pevely and Hwy. Z intersection. However, that new intersection will not include a roundabout, Wolf said.
“Yes, we anticipate switching northbound traffic off existing bridges in late November,” he said. “We will demolish the existing bridges in December.”
The roundabout installed at the intersection of the I-55 southbound exit at Pevely and Hwy. Z has been open to east and west traffic on Hwy. Z during its construction. Related work around the roundabout continues, said Jordan Dalaviras, MoDOT area liaison for Franklin and Jefferson counties.
“The roundabout at Hwy. Z is open so you are able to drive in a circle,” Dalaviras said. “There is still work as the ramps are not open to it yet.”
The new Hwy. CC bridge part of the project is anticipated to be completed in the latter part of November, Wolf said.
“The Route CC bridge over Route 67 is still under construction,” Wolf said. “We anticipate opening the interchange before Thanksgiving. Work on the median concrete barrier from McNutt (in Herculaneum) to north of the bridge over Herky Horine Road is ongoing and expected to be complete before Thanksgiving.”
The third southbound lane should open in the next couple of months, Dalaviras said.
“The southbound lane can be opened in coordination with the completion of the new interchange at U.S. 67 and Route CC,” he said. “I would say it should be before the end of the calendar year.
“(The third southbound lane and the new interchange) go hand in hand because more than half of the southbound I-55 traffic goes to southbound 67, especially at afternoon rush hour.”
The third northbound lane will open several months later, he said.
“Northbound, the third lane probably will not open until next spring,” Dalaviras said. “We don’t want to create a bottleneck at Pevely (by opening the third northbound lane before work in the Pevely part of the project finishes).”
During the period of time that MoDOT has concentrated on the Pevely area and closed the southbound I-55 exit leading to Hwy. Z (as well as the entrance from Hwy. Z to I-55), oversized-overweight trucks have been diverted to exit at Hwy. M and proceed south on Hwy. 61-67 since construction barriers on I-55 have made it too narrow for the larger vehicles.
Wolf said drivers of oversized-overweight vehicles have complied for the most part.
“Although we have had a few oversized trucks make it past the warning signs, the number has been noticeably fewer than we experienced earlier in the project,” he said. “Additional warning signs on I-55 have helped reduce the number making it to the narrow lanes.”
When the work switches to northbound I-55 in the area, similar detours will be put in place for large trucks to get off the highway at the Herculaneum exit and proceed north on Hwy. 61-67, Wolf said.
“We will continue to instruct oversized loads to use McNutt and Route M to access US 61/67 to bypass this section of I-55.”