A Missouri Department of Transportation (MoDOT) project now underway in Kansas City’s Northland will improve safety and address booming area development. The $26.2 million project in Liberty encompasses a major redesign of the Missouri 152 and Interstate 35 interchange, including the replacement of an aging bridge with a half-diverging diamond interchange.

The Route 152 corridor connects area residents to retail centers – as well as elementary, middle, and high schools – in both Liberty and North Kansas City.  With retail and other development and the accompanying increase in traffic, Route 152 had become a major bottleneck, says MoDOT’s Matt Daulton, P.E., Resident Engineer at the Nahua Project Office. “City of Liberty and City of Kansas City are fast-growing communities that offer so much commercially and are constantly growing by adding new residential and commercial developments. The interchange is extremely important to the local communities and to the entire region for freight movement, tourism and economic development and growth.

“The annual average daily traffic (AADT) along the corridor was 54,000 vehicles per 2017 figures,” he reports. “The projected AADT for 2040 is 92,000. Additionally, Federal Highway Administration crash statistics show a concentration of rear-end crashes in this corridor and warrant improved safety in the area. 

“This reconstructed interchange will allow for better traffic flow, reduced congestion and improved safety.  Additionally, the new bridge will better accommodate all users by having bike/pedestrian facilities on both sides of the bridge.”

Bridge Replacement, Additional Lanes Among Improvements

One focus of the 152 Interchange Project is the replacement of the Route 152 bridge, which had reached the end of its life expectancy.  As Daulton relates, “The previous bridge was built in 1967 and had various rehab projects to extend the lifespan of the structure. Our engineers knew that the time for the bridge to be replaced was approaching, and concerns included congestion relief, operational improvements and safety improvements. City of Liberty and City of Kansas City both identified a need for improvements to the interchange. The biggest obstacle was funding; however, City of Liberty was able to secure additional funds. “

The $26.2 million construction cost is shared among several entities, including: MoDOT, $12.7 million; City of Liberty, $6 million; Kansas City (Shoal Creek TIF), $1.5 million); and Federal Surface Transportation Funds secured by the City of Liberty ($6 million).

Daulton points out that there are in fact three projects within the contract, which was awarded to Miles Excavating, based in Basehor, Kansas:

• The I-35 and MO-152 Displaced Left Interchange (completed)
• Kansas Street improvements to add through lanes and turn lanes—along with additional pedestrian improvements and waterline installation (projected completion date August 2020)
• The Kansas Street and MO-291 intersection (projected completion date August 2020)

Major components include the bridge replacement, construction of a second bridge, replacement of I-35 shoulders, widening/extending ramps, additional through lanes (totaling to three) along Kansas Street, a 10-foot-wide shared use path along the south side of 152/Kansas that ties Liberty to Shoal Creek, additional sidewalk along the north side of Kansas, multiple MSE and retaining walls, added turn lanes throughout intersections of Kansas Street (including upgrading all facilities for ADA compliance) and storm water and waterline improvements throughout the corridor.

Reports Daulton, “The first phase was to get in the area to start construction and prepare roadways for shifting traffic. Ramp extensions were completed, I-35 shoulders were replaced, medians were removed from Kansas Street and the temporary traffic signals were installed. This was all in preparation for the new bridge.

“The next phase was demolition and erecting the new bridges. Construction of new pavement at the bridge took place as well so that the interchange would be fully functional and in the new configuration once the bridge opens. 

“The bridge work is occurred simultaneously with work on Kansas Street, to complete the construction of new lanes and turn lanes on the south side, and then focus on the north side. The last phase of the project is the MO-291 intersection.”

Interchange Design to Enhance Traffic Flow, Safety

The “Displaced Left Diverging Diamond Interchange” selected by traffic designers for the 152 Interchange Project was modeled and compared to several types of alternate interchanges (including a traditional diamond, Single-Point Urban Interchange, and normal Diverging Diamond Interchange), Daulton reports. Due to the capacity challenges, high left-turn volumes, and high through volumes, a displaced-left was determined to be the best alternative. The new bridge is projected to serve an additional 1,500 more vehicles, with 30 percent less travel time and 45 percent less delays.

There are actually two bridges, as Daulton explains. “The larger bridge is eight lanes wide and the smaller is three lanes wide. The new design allows anyone going to or coming from the north (on I-35) to be displaced onto the smaller bridge. This is a “displaced-left interchange”.  Everyone else will be on the larger bridge – if you are coming from/going to the south or staying on MO-152 across, you shouldn’t realize a change, other than more lanes.

The just-opened new Route 152 bridge was completed in approximately four months – usually bridges usually take longer to build. One goal of the transportation officials was to complete the bridge around the time school started in the fall so that the project did not interrupt school traffic.

Regarding the accelerated completion, Miles Excavating Project Manager Shawn Berkey comments, “I think that doing multiple aspects in conjunction with one another is the only way that we were able to speed up the process – installing drilled shafts at the same time we were driving pile, pouring columns and bent cap, as the MSE (mechanically stabilized earth) retaining wall was being built, and working 12- to 14-hour shifts through the rest of the build.”

Daulton says that one of the biggest on-site challenges has been coordination of all the utility companies within the project limits. “Due to the dense commercial industries and fast-growing area, there are utilities that are in constant conflict. Precautions were taken at the start of the project to make sure all companies are in constant communication and using best practices to safely and effective navigate utility conflicts.”

Bicycle and pedestrian needs along the corridor are also being addressed with the construction of a multiple-use path along the south side of Route 152 and Kansas Street, which will extend across the I-35 bridge.

MoDOT Addresses Traffic Disruptions Caused By Construction

While completion of the 152 Interchange project will bring immense benefits to area drivers, major traffic disruptions will be unavoidable while construction is underway.  Daulton reports, “There are multiple detours to divert traffic around the project. A primary route for this is MO-291 between MO-152 and I-435, which includes the interchange at I-35. Operation Green Light is an initiative of the Mid-America regional Council (MARC), where teams of traffic specialists can monitor and correct signal timing in real time based on traffic delays and queues. Prior to the bridge demolition, additional equipment was installed along traffic signals on this detour route and were already in place along Kansas Street. This additional coverage allows staff to monitor and adjust the signal and extend green time to reduce backups. 

“The largest challenge was notifying the public prior to the bridge demolition,” Daulton comments. “Our communications staff held a public meeting to bring this project into the public’s sites. They notified various police, fire, schools, and municipalities of traffic advisories and set-up a website and Facebook page designated to project specifics and updates. Our contractor even went door-to-door to businesses throughout the project to notify them directly of the upcoming bridge closure.”