After 15 years on Plymouth's wish list, a third lane is finally being added to Interstate 494 — the only stretch of the Twin Cities major arterial road that has had only two lanes.

Construction began last week, with city and state leaders holding a ceremonial groundbreaking July 23 for the much-awaited expansion of the 5-mile stretch.

"It's a project many people have thought wouldn't happen," City Manager Dave Callister said at the event, which was attended by City Council members and representatives from the state Department of Transportation, the Metropolitan Council, TwinWest Chamber of Commerce and state Legislature. " … But it's a much-needed project, not just for Plymouth, but the entire state."

Over the past decade, MnDOT has expanded I-494 through Bloomington, Eden Prairie and Minnetonka, but one final stretch remained through Plymouth with only two lanes in both directions.

Now, the $86 million, three-year project has begun, expected to wrap up at the end of 2016 and speed traffic for the 95,000 cars that travel that stretch each day.

On July 21, crews started removing guardrails and building concrete barriers to begin widening the Schmidt Lake Road, Canadian Pacific Rail (CP) and the County Road 47 bridges under I-494. In August, crews will close the Schmidt Lake Road bridge for 21 days and detour traffic to County Road 47. The County Road 47 bridge will then close after the Schmidt Lake Road bridge reopens to traffic.

The most significant delays for commuters will come next summer when construction work ramps up, with MnDOT reducing traffic to two lanes southbound and one lane northbound during the mornings, then switching for the evening commute.

"Next year, it will be unavoidable," said Scott McBride, MnDOT's metro district engineer.

But it's worth it, city and business leaders said last week, finally relieving traffic congestion on the popular roadway.

Last year, MnDOT decided to build a "dynamic shoulder" as part of the then-$68 million freeway reconstruction and bridge rehab project; the shoulder is wider than normal roadway shoulders so that it can be opened to traffic during peak periods of the day and is cheaper to build.

The city "reluctantly accepted" the idea, Callister said, but continued to push for a permanent solution.

Six months ago, McBride said MnDOT found a way: $50 million in cost savings was shaved from two other projects — the St. Croix River bridge project ($30 million) and a bridge replacement in Red Wing ($20 million). So $25 million was then added to the I-494 reconstruction, allowing MnDOT to finally fund third lanes in both directions from Hwy. 55 to the Fish Lake Interchange, where I-694, I-94 and I-494 come together. (The rest of the $25 million in savings will go toward reconstructing 50 miles of I-90 in southern Minnesota.)

"It took a great project and made it a fantastic project," McBride said.

The entire reconstruction project goes from I-394 to Fish Lake and also includes replacing deteriorating asphalt, replacing or widening 11 bridges as well as adding stormwater ponds and noise walls between now and 2016. For more information, or to sign up for e-mail project updates, go to