Construction on Olathe’s largest-ever infrastructure project entered a new phase this summer, but city officials say the biggest traffic disruptions won’t come for over a year.
With demolition complete along the I-35/Santa Fe corridor, the city began relocating utility lines this summer. Construction on the interchange itself won’t begin until late 2027.
During a presentation to the Olathe City Council last month, city engineers outlined how the $285 million project will be phased out over the coming years and what drivers can expect once construction intensifies.
Utility work
The work on the I-35 and Santa Fe interchange consists of two separate but overlapping projects called “I-35/Santa Fe Forward.”
The first, which belongs to the Kansas Department of Transportation, includes widening and reconstructing parts of I-35 between Santa Fe and 119th Street. The second, managed by the city, will rebuild the Santa Fe interchange.
Demolition and property clearing started earlier this year. Now, crews are relocating overhead and underground utility lines. This phase will continue into 2027.
Assistant City Engineer Therese Vink told the city council in June that there won’t be full road closures during this phase — only occasional lane and sidewalk closures.
Interstate work starts first
Construction on the KDOT portion of the project is expected to begin toward the end of this year and continue through 2028.
That construction will be completed in four phases including adding auxiliary lanes, reconstructing pavement and widening the Old Highway 56 bridge over I-35.
Drivers should expect some road closures during that time, including:
- Southbound Old 56 off-ramp for three months
- Old Highway 56 bridge while it’s widened and reconstructed for six months
- Northbound off-ramp at 119th Street for three months
- Southbound entrance ramp at 119th Street for three months
The intersection of Mahaffie Street and Old Highway 56 will stay open, according to city officials.
Major disruptions years away
The most significant impacts to local traffic won’t come until the city’s portion of the project reaches its final phase in 2029.
That phase, which is when the interchange will be rebuilt, includes reconstructing Santa Fe Street and extending Rogers Road.
During that time, Santa Fe will close completely. Some interstate ramps will also close, but Vink said the city will try to keep them open as long as possible.
To reduce disruptions, the city plans on completing work on surrounding streets before closing the interchange.
“We’re going to work with area businesses to put together a communication plan,” Vink said.
The entire project is expected to wrap up in 2030.
Councilmembers raise concerns about appearance
At the June 16 meeting, Councilmember Jeff Creighton said constituents have expressed concern about the appearance of the corridor now that the buildings have been demolished.
He said he has also heard complaints about the semitrailers and box trucks that are parked there.
Vink said the city will be planting temporary seed and will continue to enforce no overnight parking on the sites while utility work continues.
About the project
The I-35/Santa Fe Corridor Improvements project is the largest infrastructure endeavor in Olathe’s history, according to city officials.
The new interchange will be a single-point urban interchange, or SPUI, similar to one currently at I-35 and 87th Street in Lenexa.
According to Olathe, this type of interchange allows left-turning traffic to move simultaneously through one central signal, giving more space for large vehicles and smoother movement through the intersection.
The goal is a safer interchange with less traffic congestion.
“We know our residents want and need a faster, safer route through the heart of our city,” Mayor John Bacon previously said of the project.
