Lakeville's I-35 Interchange Rebuild Finally Has a Start Date: 2029

TLDR

• Construction on the County Road 50 interchange at I-35 is planned for 2029–2030.
• It becomes a diverging diamond — the design where traffic briefly crosses to the opposite side.
• Two new I-35 bridges, plus three noise walls that neighborhoods voted to approve.
• The state has now put roughly $46 million into it: $40 million in 2025, another $6 million this year.

If you've been hearing about the I-35 and County Road 50 interchange project for years and wondering whether it's actually happening, Tuesday night's Lakeville City Council meeting had an answer. It is. Starting in 2029.

City Engineer Zach Johnson laid out the schedule during the council's Sept. 8 work session on the draft five-year capital plan. Dakota County, which is leading the project, has published its own timeline that matches.

What gets built

The county's plan calls for two new I-35 bridges over County Road 50, replacing the existing ones.

The big change is the design. It becomes a diverging diamond interchange, where traffic temporarily crosses to the opposite side of the road through the interchange. It sounds strange the first time you drive one, but it lets left-turning drivers get onto the freeway without crossing oncoming traffic — which is exactly where crashes tend to happen. Dakota County says the project team picked it because it delivers "long-term benefits to traffic safety and mobility while also being among the lowest-cost and smallest footprint."

The project also includes improvements to trails and crossings for people walking and biking.

Three noise walls are getting built. The county put eight proposed walls to a vote of the affected neighborhoods. Three passed — Wall 3 with 71% support, Wall 8 with 64%, and Wall 6 with 61%. Four others were rejected by the neighborhoods they would have shielded.

On lane counts, Johnson told the council the new bridges will be built wide enough for three lanes but striped for two at first, since the roads north and south of them only carry two. He also said County Road 50 goes to two lanes in each direction through the interchange. Those specifics came from his presentation rather than the county's published materials.

How the construction plays out

Dakota County lists construction as 2029–2030, coordinated with MnDOT's I-35 pavement work through Lakeville.

Johnson gave the council a more detailed sequence Tuesday. Treat this as the working plan rather than a published schedule:

2029: One side closes from April to October, then reopens for the winter — everything open to traffic through the cold months.

2030: Construction starts again on the other bridge.

Throughout both years, Johnson said, two lanes of I-35 stay open in each direction. He explained why they can't do it all at once: "We don't wanna have vehicles driving underneath bridges that are under construction."

Why it took until 2029

When the project first got talked about, the target was 2026. So what happened?

Johnson addressed it directly, in case council members get asked. A big part of the delay was coordination. MnDOT has its own pavement preservation work and bridge replacements programmed for I-35 south of this corridor. The timelines kept moving back and forth.

"At this point, we think we've been able to put all of those projects together," Johnson said. "The good news is we really try to minimize the disturbances to the traveling public and our residents. So this project, in those two years, will accommodate city, county, and state transportation improvements here."

In other words: one big painful stretch instead of three separate ones spread over a decade. The county's own page confirms the construction is being coordinated with the I-35 Lakeville pavement improvements.

"It's gonna be a lot," Johnson added.

The money is largely there

Mayor Luke Hellier asked how much of the funding has actually been secured between the city and Dakota County.

"We're doing really well," Johnson said. The most recent piece is $6 million in state appropriations from the 2026 bonding bill. That follows a $40 million trunk highway award in the 2025 Transportation bill for the interstate portion of the project.

The bonding money can be spent broadly — preliminary and final design, engineering, right-of-way and easement acquisition, inspection, construction and reconstruction, including pedestrian facilities, utility relocation and stormwater work.

The city and county also have open funding applications at the federal level. Johnson's read: "At this point, I think it's fair to say that we're ready to move forward."

The near-term schedule, per the county: final engineering design and right-of-way acquisition run from late 2026 through 2028. Johnson told the council that final engineering proposals were being reviewed the same week as the meeting, and that right-of-way acquisition comes next year.

Dakota County Commissioners Holberg and Droste were both in the audience Tuesday night, and Johnson thanked them for the partnership. The county maintains a project page for the interchange with design boards and updates.

What the city is doing to soften the blow

Lakeville isn't waiting for construction to start before addressing the traffic problem.

The city worked with Dakota County to accelerate a traffic signal at Kenyon Avenue so it goes in ahead of the interchange work rather than as part of it. A second new signal is planned at Glacier Way.

Johnson was explicit about why: those are mitigating measures. The city expects "disturbances — perhaps inconveniences" during the interchange build, and wants alternate routes functioning before residents and businesses need them.

That's on top of the Dodd Boulevard rebuild in 2027 and continued development pressure along the Cedar Avenue corridor, which is bringing new retail to the area.

The Bottom Line

Nothing was voted on Tuesday — this came up during a work session on the draft 2027–2031 capital plan. That plan goes to the Planning Commission on Sept. 17 and comes back to the council for adoption in October.

But the interchange is past the debating stage. Design and right-of-way work run through 2028. Dirt moves in 2029.

If you own property near the interchange, the right-of-way phase is the piece that could touch you directly, and it's happening now through 2028 rather than in some distant year. If you just drive through it, 2029 and 2030 are the years to plan around — and the two new signals going in beforehand are your alternates.