Aiming to improve safety and mobility in the Kansas City area, the Missouri Department of Transportation (MoDOT) embarked on a $64.5 million, design-build project, adding capacity to Interstate 435 from the Three Trails Crossing Interchange to the Kansas state line.

“This corridor is the second heaviest traveled in the Kansas City region and the No. 1 corridor on the Missouri side of the line,” says Perry Allen, Project Director with MoDOT. “It was our No. 1 crash corridor as well. Most were minor crashes; property damage only.”

Even minor accidents can increase congestion and hamper traffic flow.

“Anytime a vehicle would break down in the two inside lanes, it would clog up the entire corridor, because there was no way to get them off the road,” Allen says.

More than 155,000 vehicles travel on I-435 in this area daily. The I-435 loop encircles Kansas City, and this southern portion is the longest and most developed, he said, explaining that many people live on the Missouri side and travel this road back and forth to work in Kansas.

The original six-lane I-435 was built 1966, and two lanes were added from 1983 to 1994. It was four lanes in both directions, and starting this winter, traffic flowed on five lanes east and five lanes west. The entire section was repaved with an 8.5-inch concrete overlay. The road now has 12-foot-wide inside shoulders, a 42-inch concrete barrier down the center and longer merge lanes in some locations.

MoDOT selected the Radmacher-Wilson team to design and construct the project. Quality management, maintenance of traffic, and environmental management are included in that contract. Radmacher Brothers Excavating Co., a family-owned and operated heavy contractor, established in 1981 in Pleasant Hill, Missouri, was the contractor. Wilson & Company of Kansas City, Missouri, designed the corridor improvement. The structural lead was Jacobs Engineering of Saint Louis. Trekk Design Group of Kansas City, Missouri, provided project management, surveying and stormwater improvements. Staff co-located to enhance communication and collaboration.

 Design-build was the chosen construction method for the project.  

“We needed it done quickly,” Allen explains. “We could piecemeal projects and be out there for years for each of the phases. Design-build seemed to be the best fit.”

MoDOT outlined goals and asked the industry for proposals.

“As a highway engineer, if I can get a long-life, durable rehabilitation of a current route and still allow traffic to flow during construction, it’s a wonderful combination” Allen says. “Design-build became the right way to deliver the project. For the amount of money we brought to the table and what our contractor proposed and delivered, we got great value and an awesome project.”

Allen says he would like to use design-build on additional projects in the future.

“MoDOT does design-build well,” says Ben Cummings, Project Manager for Radmacher Brothers. “A lot of the success is about a good partnership between the owner and design-builder, and it shows in the execution of the final product.”

Throughout the project communication flowed easily Allen says.

“The relationship had to have a strong level of trust,” Allen adds. “We always talked from the same perspective to get the best quality product and do it safely.” 

Scope of Work

The 3-mile expansion and paving project included replacements of four bridges at Wornall and Holmes roads, rehabilitation of the bridges at the 104th Street and UP Railway overpass, and the widening and replacing an expansion joint on a bridge crossing the Blue River. The new bridges have single-span, NU 63 and NU 53 concrete girders.

MoDOT increased the vertical clearance under the Wornall Road bridges. The new design removed columns in the roadway below the bridge.

“The pavement is wide open and clear underneath, so there is no problem with traffic and bridge elements coming together,” Allen says.

At the 104th Street bridge, Radmacher widened the eastbound span and replaced the deck slab, barrier wall, and bridge approach slabs on the remainder of the steel-girder bridge.

The Blue River bridge received widening of the eastbound bridge and replacement of the east-end expansion joint on both bridges. Radmacher accessed the bridge from the existing fill slopes, avoiding any marine work. 

Maintaining Traffic is a Major Goal

Work began in March 2018. The project was built within the existing right of way.

Radmacher divided the project into three phases, which kept four lanes of traffic moving in each direction throughout rush hours.

“We put maintenance of traffic during construction as a high item on our goals and put a lot of score to it,” Allen says. “The team got creative, figuring out how to maintain the four lanes.”

Cummings acknowledges maintaining those four lanes was a challenge. But the plan and phasing worked well.

Initially, the contractor shifted traffic to the middle and widened to the outside. In phase two, crews shifted the traffic to the new lanes on the outside, so the interior lanes could be built and paved.

“Once traffic adjusted it worked well,” Allen recalls. “We got through it without a major incident.”

The final phase moved traffic to new pavement on the outside, while the final paving operations took place. Radmacher then constructed the remainder of the Holmes and Wornall bridges and built the median deck replacement on the 104th Street Bridge.

The contractor used GPS guidance for the earthwork, and paved using a GOMACO paver with a smoothness indicator, which led to a great ride quality, Allen adds. Radmacher used Antigo rubblizing equipment to break up the old concrete and recycled it. The project remained under budget and on time.

“The hallmark of the project was about traffic volume, safety of the workers and traveling public, and to provide good value,” Allen concludes. “We’re happy with the project.”