By next summer, a new roundabout will replace a traditional a traffic signal at a busy and often congested intersection in downtown Prior Lake, and Lois Kocon isn’t convinced it will make things any better.

“It makes me anxious,” said Kocon, who lives near the new circular interchange that is being built by Scott County and two other agencies on Hwy. 13 and County Road 21. “You are at the mercy of the person to your right. A lot of people are concerned how that will work. Is it going to solve a problem? Will it make the problems worse?”

Kocon wanted to know if roundabouts really deliver the safety and traffic flow benefits that experts say they have. So she asked Curious Minnesota, the newspaper’s community-driven reporting project, to find out.

With only about 5,000 roundabouts on the nation’s roads — making them still somewhat uncommon — it’s natural that drivers might consider them confusing. But Jim Brainard, the mayor of Carmel, Ind., is a big proponent of them. He spent time studying law in the United Kingdom and marveled at how efficiently traffic flowed through them. In 1996, he brushed off ridicule and brought the first roundabout to Carmel. Now with 126 of them, the city just north of Indianapolis is virtually traffic light free and unofficially known as the “Roundabout Capital of America.”

“I’m responsible,” he proudly says, touting the results that have come with them. Property-damage crashes at Carmel’s roundabouts are down 40%, and crashes with injuries have dropped by 75%. Insurance rates have dropped, and drivers have saved gas with less stopping and idling at traffic signals.

Results in Carmel mirror what has occurred nationally where the Federal Highway Administration (FHWA) and the Insurance Institute for Highway Safety have found a 37% decrease in total crashes and a 75% drop in crashes resulting in injuries when compared with traditional signalized intersections. Fatal mishaps dropped by 90%. Wrecks involving pedestrians declined 40%, the data found.

More than 10,000 motorists died at intersections in 2018, according to the FHWA, and fatalities often resulted from head-on, right-angle or T-bone crashes in which another driver ran a red light or was making a turn. Roundabouts have a favorable safety record because motorists are generally moving in the same direction and traveling at slower speeds, said Joe Gustafson, a traffic engineer with Washington County Public Works Traffic Operations.

It’s not that crashes don’t happen, but they are more likely to be low-energy sideswipes or rear-enders that tend to bring less serious consequences, he said.

“You are generally cleaning up glass and not blood,” he said.

Traffic flow has improved, too, Gustafson said. When the intersection of Manning Avenue and Hwy. 96 was governed by a four-way stop, it was not uncommon for quarter-mile backups to develop weekday afternoons on Manning. After the roundabout opened in 2016, “those backups went away completely.”

That’s been the case at several of the other 17 roundabouts in the county where there will be 21 by next year, Gustafson said.

Alleviating congestion in downtown Prior Lake is the major driver behind the construction of the roundabout on Hwy. 13 and another one nearby, said Scott County engineer Tony Winiecki.

When approaching a roundabout, drivers should yield to traffic already in the circle, then enter when there is a gap. When approaching a roundabout with two lanes, a driver who wants to exit to the right should pick the right or outside lane. Drivers who need to make a left turn should choose the left or inside lane. Drivers going straight can choose either lane. When entering a two-lane roundabout, drivers should yield to traffic in both lanes, Gustafson said.

The biggest mistake, mostly at roundabouts with two lanes, is “drivers treat them like merging onto a freeway and that they should never stop at the entry,” Gustafson said. “They need to wait at the entry until traffic is clear.”

Though some drivers are still apprehensive about roundabouts, concerns and anxiety generally go away — or at least way down — after they drive or walk through them, said Jeff Shaw,Intersections Program manager with FHWA. In Prior Lake, officials next spring plan to hold educational events to demonstrate how to navigate a roundabout.

“You see a complete 180,” Shaw said. “That was not so bad, people say. Our focus is on saving lives and this one does a remarkable job. We are encourage states to use them as often as we can.”

Washington County has been a leader in Minnesota in roundabout education and developed an outreach program to educate drivers called Roundabout U.

Roundabouts across the country are appearing at a rapid pace. Wisconsin has the most roundabouts with 432, and Minnesota, with 252, ranks in the Top 10 nationally.

The roundabout at Hwy. 13 and County Road 21 to be completed by July 2020 is anticipated to reduce traffic delays by 85%, and crashes resulting in serious injuries are expected to drop by 75%, according to Nicole Schmidt, a project spokeswoman. Those are numbers Brainard said should allay Kocon’s fears.

“She will be a lot safer as a driver,” he said “She will learn to love it.”