The Kansas Department of Transportation (KDOT) is extending the north end of the Interstate 35 bridges in Olathe, Kansas, to accommodate a city street being expanded below to better serve an international company’s expansion. The larger headquarters will result in increased traffic to an already heavily congested area.

“The main purpose of the project was to ease congestion on the interchange to the south at 151st Street,” says Nathan Jeffries, Construction Engineer with KDOT.

The project is a public-private partnership between KDOT, Olathe, and Garmin, the company that is expanding. The project received state funding due to its promotion of economic development in the area.

“The city of Olathe paid for the engineering of the work on I-35 and received a grant from KDOT’s Economic Development Program to pay for the construction work on I-35,” said Nate Baldwin, Assistant City Engineer for the City of Olathe.

The I-35 bridges carry about 75,500 vehicles per day. Garmin International’s 96-acre headquarters and service center is located near the interchange in Olathe. This project will ease access from the north for entry to that complex, which the company is adding on to.

Garmin, a GPS navigation pioneer, began the second stage of its $200 million, design-build 544,000-square-foot expansion in January. The project will create an aviation business center, with a simulation area, labs, fitness center and dining space in a former warehouse and manufacturing site. It will require hiring an additional 1,400 employees.

In 2018, Garmin doubled its manufacturing and distribution facilities in Olathe. The current addition will bring the square footage to 2.25 million and 5,400 employees. Gould Evans in Kansas City, Missouri, designed the project, and McCownGordon Construction, also of Kansas City, Missouri, is building it – both under a design-build contract. Completion is expected at the end of the year, soon after the road improvements wrap up.

“Currently the I-35 interchange at 151st Street experiences daily morning commute backups,” says Brooks Fairman, Project Manager with KDOT. “Access to Mahaffie Street from the I-35/Old U.S. 56 exit will help reduce the backups by giving Garmin employees another access.”

HNTB of Kansas City, Missouri, designed the $5.4 million bridge project, and H.W. Lochner of Chicago drafted revisions suggested by the contractor to save money and time. The change involved retaining rather than removing, the original abutments.

Crews are building two 98-foot-long bridge extensions, one northbound and one southbound; 14-foot-tall mechanically stabilized earth walls; two new abutments; and using sliding plate expansion joints to carry traffic from the existing bridges to the extensions. When complete, the bridges will be 480 feet long.

“There are two bridges in a row, the existing and the new extension north of it,” Jeffries says.

The bridges span two BNSF rail lines, but the current work is not interfering with train traffic, and Mahaffie Street. The city of Olathe is extending Mahaffie’s existing terminus of 151st Street under I-35 to Old 56 Highway and Church Street, about two-thirds of a mile. The city acquired additional right of way, and Garmin donated land for the extension.

“It will help with the traffic flow in that part of the city,” Baldwin says.

The extended city street will accommodate more traffic related to the Garmin expansion, which is partially funding the expansion through a development agreement, contributing $1.8 million. The project also received $6 million in city funding.

The improvements include pavement, curb and gutter, storm sewer, street lights and sidewalks. A new 12-inch waterline is also being installed along the new roadway to address water pressure issues on the east side of I-35, Baldwin says.

Pyramid Contractors of Olathe received the city contract. The state project began earlier than the city project, Jeffries says, adding that the bridge work is not interfering with the local project. Additionally, all entities have been cooperating. Once the bridge work is complete, the city will finalize the work under it, with completion scheduled for the fall of 2020.

“We are pleased with how everything is progressing and thrilled to have the opportunity to alleviate traffic congestion on one of the most traveled roadways in Olathe,” Baldwin says.

Pyramid Contractors also received the $5.4 million contract to extend the state’s bridges. The company was founded in 1994 as a bridge contractor and has expanded over the years to perform other civil work. Construction began on northbound I-35 in June 2019.

The northbound bridge was extended in 2019, and no work took place over the winter. The contractor is progressing on phase two, the southbound bridge.

Most of the work takes place during the day. I-35 normally has three lanes in each direction. During construction, it is down to two lanes southbound and one lane northbound. The traffic is directed through a shoefly with temporary barrier walls.

Kelly Kultala, a Public Affairs Manager for KDOT, has partnered with the city to keep residents informed with press releases, and Facebook and Twitter updates and responses to citizen questions. Kultala said she is pleased that the project is continuing KDOT’s mission to provide citizens a statewide transportation system to meet the needs of Kansas. The KC Scout program captures images of traffic and sends information about delays, vehicle accidents or blocked lanes to digital message boards and social media. Drivers can then decide whether to take an alternate route.

“We coordinate with KC Scout if there is a traffic switch,” Jeffries says.

Jeffries indicates an easy alternate route is not available and that the wait time would still be less than getting off the interstate and navigating city streets.

“Traffic delay is less, around 14 minute during peak rush hour times,” Fairman adds.

Drilled shafts, reaching to a depth of 30 feet, support the new extension of the bridge. The piers for the new extension are adjacent to the piers for the existing bridge. The project remains on track for an August completion. KDOT and contractors meet weekly.

I’m proud of “being able to partner with the team, consisting of the KDOT, the contractor, and the consultant designer, to work through a different and challenging approach to construct the project,” Fairman concludes.