WILLMAR - Travelers who will use the redesigned U.S. Highway 12 on the west side of Willmar as part of the Willmar Wye project will have a bit of cylindrical route once construction is completed.
Bolton and Menk, part of the Hoffman Team hired by the Minnesota Department of Transportation to design and build the road portion of the Willmar Wye project, has proposed constructing two roundabouts on the new section of Highway 12, both as a cost savings and safety measure.
MnDOT conditionally approved the plan as long as the city and county did. Both the Willmar City Council and the Kandiyohi Board of Commissioners unanimously approved the updated design this week.
The first roundabout will be located at the new intersection of Highway 12 and County Road 5, which will be located approximately 650 feet south of the current intersection.
Instead of putting in a large traffic signal intersection, Bolton and Menk thought a roundabout made much more sense. This option removes the costs of the traffic signal and any future maintenance on the signal.
"There is a significant costs reduction associated with this," Wardford said. "We are not spending a quarter of a million dollars on a traffic signal."
The second proposed roundabout to be constructed is at the new intersection of Highway 12 and 1st Avenue. A roundabout here will help Willmar Industrial Park traffic, including trucks, to enter Highway 12 without having to worry about merging into traffic going 60 to 70 mph. The original design called for only a stop sign and a truck acceleration lane, but Wardford said there were still concerns about safety.
Both of these roundabouts will be large, at least 146 feet in diameter. Regular-sized tractor trailers will be able to navigate them, Wardorf said. Even larger vehicles, including trucks carrying wind turbine pieces or bigger, will be able to get through them.
"We had to demonstrate to MnDOT that larger vehicles can access all routes through these roundabouts," Wardford said.
Roundabouts have been shown to increase safety on roads and reduce fatal and severe-injury crashes.
"Most of the reason for that is speed reduction. You cannot navigate a roundabout at high speed, they are not designed for that," Wardford said.
This will be an added benefit for the new Highway 12 section which goes through land that in the future could be developed as part of the Willmar Industrial Park. The roundabouts will keep vehicle speeds down in that area.
"I see that as a pretty significant safety benefit," Wardford said.
He said the design team also took a look at how the Highway 12 and County Road 5 intersection would work when a train is blocking the crossing. If a train is blocking the crossing for more than eight minutes during the regular work day, traffic could back up all the way into the roundabout. Wardford said the lane size of the circle, 24-feet wide, would make it possible for drivers needing to navigate the circle to do so, even if a line of cars are stopped on the right-hand side. Signage could help with this as well, Wardford said.
The main goal of the Willmar Wye project, to allow trains to travel between the Morris and Marshal subdivision tracks without having to turn engines around in downtown Willmar, could reduce how often trains are blocking the road crossing.
"The biggest driver of delay at the railyard are trains that come in and need to switch," Wardford said. "They won't have that conflict anymore."
Construction on the Highway 12 and County Road 5 roundabout is scheduled to begin this year. This project does have the chance of overlapping with the county's roundabout project on County Roads 5 and 15. Both projects will have detours.
"We have to get out there this summer. We don't want to lose a year of construction," Wardford said.