Salem ―Back when the intersection of Routes 82 and 85 had four corners, there were 134 collisions in the five-year span before officials decided to replace the dangerous crossroads with a roundabout.

The roundabout, finished a decade ago now, came after several years of planning. A federal infusion of $3.5 million paved the way for the transformation of the signaled intersection. The intent was to reduce crashes; there were 52 of them with injuries from 2003-08. One was fatal.

Department of Transportation (DOT) project manager Scott Bushee said the state’s plan worked. The five-year preconstruction average of 22 crashes and nine injuries annually was reduced to 10 crashes and one injury annually from 2014-19, according to his analysis of data from the Connecticut Crash Data Repository.

“We’re showing a 90% reduction in injuries,” he said. “That’s huge.”

The first roundabout in the state built to replace a traffic light, it followed similar improvements at non-signaled intersections in Milford, Killingworth and West Haven.

A roundabout avoids left turns by sending all traffic counterclockwise around a center island. That cuts down on the t-bone and head-on crashes that cause the most serious injuries.

The DOT said a study of five state-constructed roundabouts found an 81% reduction in severe crashes and a 49 percent reduction in total crashes. There are currently 15 roundabouts on state roads. More than a dozen are in the planning phase – including six on one strip of Route 82 in Norwich.

Advocates then and now say the Salem roundabout makes the commute more efficient for people driving between New London and Hartford as well as beachgoers on their way to and from the southeastern Connecticut shoreline. Town leaders at the time touted it as a way to help revitalize the town’s commercial center.

A headline in the Day archives shows the roundabout was “said to be confusing” back in 2013. There were complaints about the double lanes on one side of the roundabout that gave drivers heading north on Route 85 or east on Route 82 two options when entering.

Bushee said the two lanes were included to address heavy afternoon traffic from commuters working in the New London area who turned left at the intersection to get to Route 11 and points north, like Colchester and Hartford.

Ten years in, reaction to the roundabout is mixed.

Hugh McKenney, a former Salem selectman and resident for 27 years, said traffic before the roundabout was installed would sometimes back up a half mile on Route 85. The congestion made it difficult for him to pull out onto the state road from his street during the beach season.

“Since the roundabout has gone in, I have never had that problem again,” he said. “The traffic flow in the summer is much easier, and moving through the roundabout is very efficient, even on the busiest summer weekends.”

French-born Salem resident Marina Bogart said roundabouts are much safer than traffic lights, but called into question the design of the one in Salem.

“People coming from New London almost have a straight line if they continue on Route 85 towards the (Salem) school,” she said of one of the areas with two lanes. “It does not make them slow down.”

Hailing from the European country known for having the most roundabouts, she said she welcomed their proliferation in Connecticut despite her reservations about the Salem model.

“They need to be part of the learning program when getting a license,” she said. “Many new drivers have no idea how to deal with them.”

Traffic expert Joe Balskus, vice chairman of the National Institute of Traffic Engineers’ roundabout standing committee, described the reduction in crashes in Salem as “spectacular.”

The director of transportation systems at the engineering Firm VHB, he oversaw the conversion of Franklin Square to a one-lane roundabout last year in Norwich.

While he was not involved in the Salem project, he said he keeps track of projects throughout the state based on his 15 years spent studying, designing and building the traffic circles.

He described the Salem roundabout as “oversized” for the number of cars that use it.

That’s because 20-year traffic volume projections used to shape the design and the number of lanes have not yet materialized, according to Balskus. He suggested the state should have built the roundabout with one lane to start and then added the other lane if projected volumes were realized.

A guide from the U.S. Department of Transportation said double-lane roundabouts introduce more opportunities for collisions, which makes it important to use the fewest number of lanes traffic volumes require. But the guide said roundabouts with more than one lane typically produce low-speed crashes that are less severe than the kind that happen in intersections with traffic signals.

“The minus is the volume didn’t materialize so they didn’t need all those lanes,” Balskus said. “But the positive is that it’s actually working to reduce crashes and congestion.”

Bushee, the project manager on the Salem roundabout serving now as project manager for Norwich’s Route 82 project, said the circles planned at the eastern end of Route 82 closer to the city center are slated to be one lane. The ones at the New London Turnpike end of Route 82 are not as far along in the design process, but may contain additional lanes.

A common complaint about roundabouts is the failure of many drivers to yield. Talk on the Salem Facebook page about the roundabout is filled with stories of near-misses.

It’s a common complaint, according to Bushee. He fields calls often from people saying they “almost” got hit.

He tells them that’s the key word.

“Speeds were low, you were able to avoid the crash,” he said. “There was no crash. There was no injury.”

e.regan@theday.com

Editor’s note: In an earlier version of this article, McKenney’s elected status was incorrect.