About 25 people showed up at Arnold City Hall last week to learn about the upcoming rehabilitation work to the Meramec River bridges on I-55 in the Arnold area, Missouri Department of Transportation officials said.
MoDOT held the June 17 open house to discuss the project, which is expected to start in December or early 2026 and be completed in late 2027.
Jordan Dalaviras, MoDOT area liaison for Jefferson and Franklin counties, said he was pleased with the turnout at the open house, adding that most of the people who attended didn’t know the extent of the project.
“Those people will take the information to their families and friends to spread the message,” Dalaviras said.
The bridge project calls for routine maintenance and repairs, as well as resurfacing and repairing deteriorated sections of the decks on the twin bridges over the Meramec River – the bridge on northbound I-55 and the bridge on southbound I-55.
Dalaviras also said MoDOT will touch up the bridges’ joints, work on the bridges’ substructures and address erosion issues on the north side of the bridges in south St. Louis County.
He said the main issue people wanted to know about is how the work will impact them while traveling on the bridges that connect Jefferson and St. Louis counties.
The work will be completed in four phases, and MoDOT intends to keep as many lanes open on both bridges during the project. The southbound bridge has five lanes and the northbound bridge has six lanes.
“Hopefully, it will be minimal impact,” he said. “I think the outcome of talking with everybody is very positive. As they learn, know and hear the message from us, they are very happy with the outcome.”
MoDOT will close the northbound Hwy. 141 left turn lane that leads to the on-ramp, and southbound Hwy. 141 drivers will need to yield before entering the on-ramp, according to the website.
During the first phase, crews will work on the west section of the southbound bridge, and two southbound lanes will be closed and instead diverted onto the northbound bridge, leaving three open lanes on the southbound bridge. That will leave four northbound lanes open.
For phase two, crews will work on the three southbound lanes that were open during phase one. That will shift southbound traffic to the two completed lanes on the west side of the southbound bridge, and drivers will continue to use those two lanes to travel south on the northbound bridge with the other four lanes remaining open for northbound traffic.
Phase three will shift the work to the northbound bridge, with work starting on the two lanes on the east side of the bridge. Three of the northbound lanes will remain open on that bridge, and two lanes will be closed and instead diverted onto the southbound bridge. Four lanes will be open on the southbound bridge.
During the final phase, three lanes on the west side of the northbound bridge will be closed, and drivers may use the two lanes completed during phase three to travel north as well as two northbound lanes on the southbound bridge, which will have four lanes open for those traveling south.
Dalaviras said MoDOT did consider closing an entire bridge at a time, which would have reduced the number of lanes open to traffic on the other bridge.
“This allows for as much traffic to flow as possible,” he said of the plan to only close two to three lanes on bridge at a time. “We figured that was the best outcome. If we get comments that people really want it the other way (full bridge closures), that could change.”
Dalaviras also said MoDOT spoke with first responder agencies in the area to make sure the plan did not hinder them.
Those who attended the open house in Arnold had the chance to fill out a comment form to provide suggestions or ask questions about the project.
Comment forms may also be completed online at modot.org/projects/interstate-55-bridge-rehabilitation-jefferson-and-st-louis-counties. The comment form will be available through July 1.
“Hopefully anyone who didn’t make it (on June 17) will access it (the plans and comment form) online,” Dalaviras said. “They will know the impact of the work and that it will not really close things down, and it will allow traffic to flow as best as possible. We are more than happy to answer questions.”
The bridge project is one of the 12 Jefferson County projects included in the proposed Statewide Transportation Improvement Plan (STIP) for fiscal years 2026-2030. The $17.8 million project to rehabilitate the twin bridges over the Meramec River will be covered by a combination of federal and state funds.
The work zone will extend about 2 miles between Hwy. 141 in Arnold and Meramec Bottom Road in St. Louis County.
The same bridges are listed in the STIP for a 2028 project that involves painting the bridges at an estimated cost of $9,428,000.
According to plans on MoDOT’s website, modot.org, the project is expected to be completed in late 2027.
Jeffco Boulevard/Hwy. 61-67 project
Dalaviras said the work to improve the area where St. Johns Church Road, Linderhof Drive and Jeffco Boulevard intersect in Arnold and to improve safety at the intersection of Hwy. 61-67 and Miller Road East just south of the Arnold city limit is going well.
On June 16, MoDOT closed lanes on Jeffco Boulevard in Arnold to mill and replace asphalt. It also began closures on the portion of St. Johns Church Road that intersects with Jeffco Boulevard from 7 a.m. to 3:30 p.m. each day.
Drivers may still travel north and south on Jeffco Boulevard, but there are lane shifts during the work that is expected to be completed Monday, June 30, according to MoDOT.
St. Johns Church Road is open where it intersects with Richardson Road during the project.
Dalaviras said while traffic signals have been installed where St. Johns Church Road, Linderhof Drive and Jeffco Boulevard intersect, and those traffic signals are expected to be turned on after milling and asphalt work is completed.
“There will be ample notice before those signals are turned on,” he said.
Dalaviras said MoDOT will put out changeable message sign boards to alert drivers about the signals being activated, adding that when the signals are first turned on, there will be blinking yellow lights for Jeffco Boulevard traffic and the lights will blink red for the cross streets.
“There is a sequence of flashing for a time frame,” he said. “Then we will go fully into the signal running full cycle.”
The entire $2.5 million project involving the two intersections is expected to be completed later this summer, according to MoDOT.