Richfield is on its way to becoming the roundabout capital of Minnesota — not so much for the number of its traffic circles as for their prominence.

The City Council recently authorized adding two new roundabouts as part of a complete reconstruction of 66th Street, often called the city's unofficial Main Street. The double-wide roundabouts will be installed at Nicollet and Lyndale avenues, two of the busiest north-south thoroughfares in the city.

Along with existing roundabouts at Portland and 17th avenues, they'll have motorists circling at four of the city's biggest, busiest intersections.

"Throughout the process, we've kind of tagged 66th Street as the Roundabout Corridor," said Jeff Pearson, the city's transportation engineer. "It definitely will be a focus of attention from other communities, as they're looking at [installing] these as well."

Roundabouts have long been common in Europe, but they're starting to catch on in the United States. Minnesota has just under 200 roundabouts, with more being added every year.

The Minnesota Department of Transportation recently changed its engineering guidelines to give roundabouts equal weight with traffic signals in highway design decisions. The department has tracked two dozen intersections that switched from signals to roundabouts and found about a 60 percent reduction in injury crashes and an 80 to 90 percent reduction in fatal crashes — all while moving more traffic through the ­intersections.

The new roundabouts will have an additional safety feature for pedestrians, Pearson said. The city is planning to install rectangular rapid flashing beacons, or "RRFBs." Crosswalks in the roundabouts will have a push button for pedestrians to activate the extremely bright flashing lights. Traffic studies have shown that the lights improve the rate that vehicles yield to pedestrians by as much as 90 percent, Pearson said.

Richfield considers the intersection of 66th Street W. and Lyndale Avenue S. to be the heart of the city's downtown, Pearson said, and so that roundabout will get special landscaping befitting its prominence.

"We're looking at sculptures in the center — some kind of art element," he said.

Richfield's council did reject proposed roundabouts at the entry-exit ramps for Interstate 35W at 66th Street. Council members felt the layout of surrounding streets wouldn't mesh well with the traffic flow from the roundabouts.

The 66th Street reconstruction is being handled largely by Hennepin County, with work scheduled to get underway in 2016 and be ­completed by 2018.

John Reinan