Massive west-side road project starts soon — and will last two seasons

If you use West 41st Street or Marion Road, get ready to make some adjustments to your routes.

A two-year, $44 million construction project is starting soon, including around and north of 41st Street and Marion Road and ultimately including the intersection of 41st and Interstate 29.

“As we continue to see traffic go up in this corridor and the west side continuing to grow with new businesses to the east, we need to accommodate traffic flow in that area,” city engineer Andy Berg said.

“A big chunk of that is adding the third lane in each direction west of the interchange, getting that flow over to Marion Road, and safety is always a piece of this.”

The new “diverging diamond” interchange is designed to move traffic more efficiently and eliminate having to cross traffic when turning onto the interstate.

“It’s kind of a crisscross,” Berg said. “You crisscross through a signalized intersection. … It avoids having to wait at a green to take a left if you don’t have an arrow and avoids the conflict of the T-accident scenario.”

First, though, 41st Street from Marion to Meadow Avenue, which is near IHOP, will be under construction. Starting next month, the north half of 41st will be worked on first going west, and then traffic will flip-flop later this year.

“So there will always be a single lane in each direction,” Barg said.

Marion Road also is going to be reconstructed from 31st to 39th streets, so the north half will be closed first for about a month followed by the south side for about a month. That whole thing likely will take until July.

“There are detour routes,” Berg said. “Big picture, for commuters, we recommend 12th, 26th and 57th as efficient ways to move east-west across town. They can go through 41st, but we definitely want them to be patient.”

Here’s what 41st Street will look like when it’s done:

2023 plan

Next construction season, work will move to the interchange and include 41st Street east to Shirley Avenue. Details on how that will be phased haven’t been confirmed yet.

“That will be the heavier interstate impact,” Berg said. “In 2022, this year, I-29 will be relatively unaffected. The off-ramps and on-ramps will all function as normal. It’s just if people want to head west on 41st is where they’re going to run into a single lane.”

Here’s a full look at the project:

There will be some cleanup work and landscaping done in 2024, but the plan is to have all the roads operational by the end of 2023.

And this likely won’t be the last you hear about “diverging diamond” interchanges. There’s one that’s going to be under construction in Rapid City involving I-90 this year, and there is the potential to add them at I-229 and Benson Road in Sioux Falls and I-90 and Splitrock Boulevard in Brandon.

To learn more

The city of Sioux Falls, in conjunction with the South Dakota Department of Transportation, will host a public open house from 4 to 7 p.m. Thursday, March 17, at The Empire Mall to provide information on the 41st Street project. Organizers suggest using the northeast door near JCPenney and Red Robin.

Information about the project and construction phasing will be shared at the open house. Members of the project team will be available for one-on-one conversations and to answer questions. More information about this project can be found at siouxfalls.org/41st-ddi and by following the hashtag #41stDDI on social media.