Workers are nearing completion of Dakota County's first multilane roundabout at the busy intersection of county roads 50 and 60 in Lakeville.

And it's turning out to be far more expensive than planned.

The county originally estimated the project would cost about $9.5 million. But land purchases and other unforeseen expenses have pushed the price tag to nearly $11.4 million. It's the latest in a number of transportation projects that have come in over budget this year.

County staff said Lakeville should pay for $1.1 million of the overrun, an amount City Council Member Doug Anderson called a "huge, huge number."

"It's really, quite frankly, pretty devastating," Anderson said at a meeting on the project last week. City officials questioned whether they should be on the hook for that much money. How expenses will be divvied up has not yet been finalized.

The project is set for completion around Aug. 28 — if the weather holds out. If there is nice weather for the remainder of the project, costs could drop, Dakota County Engineer Mark Krebsbach said.

Residents and businesses will be glad to see the roads reopen, said Dr. Kamran Ahrar. He hears a lot of grumbling from customers at his Advanced Family EyeCare office next to the intersection.

Since May, drivers have been rerouted along 175th Street to Ipava Avenue.

"People are usually 10 minutes late," Ahrar said. "They are frustrated with the detour."

Ahrar is optimistic about the multilane roundabout. People who are elderly and not accustomed to traffic circles may be nervous, Ahrar said, but overall he thinks it will ease problems at the site.

"It would get quite backed up," he said. "People would be sitting at a light for quite a while."

More roundabouts

The roundabout will move traffic faster and result in fewer accidents, Assistant County Engineer Brian Sorenson said. The crashes that do occur are more likely to be sideswipes than T-bone collisions, he added.

Roundabouts are growing in popularity. There are at least 24 already built or in the works in Dakota County, according to county estimates.

A couple of those have two lanes in part of the roundabout, but the circle at County Road 50 (also known as Kenwood Trail) and County Road 60 (also known as 185th Street) is the first to have two lanes the entire way around, Sorenson said.

Educational videos and documents are posted on the county's website and staff is sending postcards to neighbors with information on the roundabout, Sorenson said.

To accommodate growth and increasing traffic in Lakeville, the county is also adding a fourth lane to sections of county roads 50 and 60 as part of the project.

Three-lane roads — one lane in each direction with a turn lane in the middle — typically can handle about 18,000 vehicles daily. By 2030, between 19,000 and 27,000 vehicles will travel County Road 50 on a given day, according to the county.

So a fourth lane of County Road 50 is under construction from the County Road 60 intersection north to Jurel Way. County Road 60 will also have a fourth lane from the roundabout west to Orchard Trail.

Calculating costs

Buying land for the roundabout and new lanes has been expensive.

The right of way the county needed to purchase from property owners has cost, on average, 38 percent more than initial appraisals, Sorenson said.

It can be difficult to calculate right of way costs, county staff said.

"It's not unusual for us not to know the full right of way costs until after the project is open and people are using the road," Krebsbach told Lakeville officials, because it can take years to go through the condemnation process.

Utility relocations and the addition of a railroad crossing also increased the price. Lakeville officials did not get details on the cost changes until June 3, and said they were irritated that the county did not tell them sooner.

"We're taking this seriously, too," Krebsbach told city officials as he explained the cost overruns. "They do happen on occasion. It's not the norm."

But such miscalculations have been fairly common lately for Dakota County. In 2015, the county has had five major budget amendments to transportation projects, totaling $4.9 million, Krebsbach said. That's nearly three times the average annual cost of budget amendments, according to county data from the previous six years.

The County Board has approved three of the amendments, and two will come before the board soon.

Faced with the spate of expensive changes to projects' price tags, county staff recently evaluated cost estimating and budgeting practices. Krebsbach told the County Board in June that staff are making changes that will allow them to update projects' budgets earlier in the development process.

Jessie Van Berkel • 952-746-3280