Accidents increased fivefold when the exceedingly congested intersection at State and Ellsworth became the county’s first two-lane roundabout in late 2013, from twenty-nine in 2012 to 168 in 2014–instantly making it the county’s most crash-prone intersection. Then, in 2015, they dropped by a third, to 114. How come?
“We weren’t happy,” says Pittsfield police chief Matt Harshberger, whose department oversees the intersection. “We reviewed the data and talked to the city of Ann Arbor and the county road commission. The most significant thing was that folks did not know how to maneuver through a multilane roundabout. Folks were not yielding to both lanes, and that was causing angle, sideswipe, and same-direction crashes.”
Pittsfield responded with more traffic enforcement, Harshberger says, and “also did education and warnings.” And last October, the road commission changed some signage. “We had these squirrelly looking symbols there that looked like fishhooks that were confusing to drivers,” says senior project engineer Mark McCulloch. “We went to standard left and right signs.” Overhead signage also is in the works.
“The target is for people to get in the correct lane,” McCulloch says. “We’re hoping lane-use signs will reduce crashes or cutting someone off and help people get comfortable with the roundabout … It’d be nice to get it down to fifty or sixty [accidents] a year.”
Even that would still be twice the old level, but McCulloch and Harshberger consider the roundabout a success in two critical areas: Traffic is moving through the intersection more efficiently, with fewer backups. And though the number of crashes is up, the severity is way down. “We’re seeing way more property damage crashes,” Harshberger says, “and way less personal injury crashes.”
Harshberger says complaints about the roundabout also are “not as frequent. We got quite a few the first year. Learning curve was big on this one.”
McCulloch says more roundabouts are coming. “We’re starting one at Scio and Wagner in 2017. It’ll be a much smaller, rounder roundabout.”
