Roundabouts proven to be safer than traditional intersections
North Strabane Police Capt. Matthew Mancini admitted to being somewhat skeptical when the Pennsylvania Department of Transportation recommended double roundabouts to replace the dangerous intersection at Brownlee and Thomas-Eighty Four roads.
About nine years later, the previous site of numerous crashes has seen a significant reduction in traffic accidents.
“Absolutely,” Mancini said. “Prior to them putting the double roundabouts in, the way the intersection was configured, it was not handling the increase of traffic that (Route) 519 saw due to development in the Eighty Four area. We had a lot of bad crashes at that intersection prior to the roundabouts. Since they’ve put those in, we’ve seen a major reduction in serious crashes there.”
A recent PennDOT study revealed that at locations where traditional intersections were replaced by roundabouts, crashes involving injuries were reduced by 51% and the total number of crashes was reduced by 7%. During a 20-year review period, there have been only two fatalities at roundabouts.
PennDOT evaluated 47 roundabouts on state routes at intersections that were previously stop- or signal-controlled with at least three years of crash data available before and after the roundabouts were built and had at least one crash during the 20-year review period.
The two connected roundabouts on Route 519 were included in the study, as well as one on Interstate 70 and Wilson Road in Bentleyville. Also, the roundabout at Morgan Road’s intersection of Route 1009 (Morganza Road) and Baker Road in Cecil Township was one of eight new roundabouts in the latest review. That roundabout, which opened in 2021, was constructed in conjunction with the Pennsylvania Turnpike’s Southern Beltway Project.
“Roundabouts have proven to be an irreplaceable tool in reducing crashes at intersections,” said Mike Carroll, PennDOT secretary. “Given the dramatic increase in safety and traffic flow, PennDOT will continue evaluating intersections for roundabouts.”
A roundabout is described as a circular intersection where traffic flows around a central island in a counterclockwise direction. Roundabouts are designed to be safer and more efficient than traditional interactions, and are often used in place of stop signs or signal-controlled intersections.
PennDOT routinely evaluates all major intersection improvement projects and measures elements like vehicle delay, number of crashes, crash severity, maintenance costs, environmental impacts and topography. Input is gathered from the local government and community.
Roundabouts also have been recognized by the Pennsylvania State Transportation Innovation Council as an innovation that has become standard practice within the transportation community.
“Modern” roundabouts have been built in the United States since the 1990s, although the history of such “traffic circles” dates back to 1905, when Columbus Circle opened in New York City.
The first roundabout in Pennsylvania appeared in 2005 in East Marlborough Township in Chester County. However, it was built through a highway occupancy permit and not a state contract.
The first PennDOT modern roundabout built through a state contract (the third in the state) opened in 2007 in Spring Grove Township in York County.
Currently, there are 95 on Pennsylvania roads.
“There is no one-size-fits-all approach (as to where they are constructed),” said Zachary Appleby, PennDOT deputy communications director. “We consider the factors to determine the appropriate solution at any given location, but the implementation of roundabouts has been increasing over time.”
Appleby said roundabouts typically are safer because they slow vehicles, prevent T-bone or head-on collisions and eliminate left turns across opposing traffic.
The Federal Highway Administration (FHWA) also supports roundabouts as a safer alternative to traditional intersections and they are an integral part of the administration’s Every Day Counts Initiative. FHWA data shows roundabouts reduce fatal and injury crashes by 80% versus two-way stop-controlled intersections and by more than 75% versus signalized intersections.
PennDOT has some tips to remember when navigating a roundabout:
Slow down.
Yield to traffic and pedestrians, which may require stopping. (If there are multiple circulating lanes, yield to both before entering. Do not assume the vehicle in the inside lane will stay there.)
Do not stop in the circulatory roadway.
A video detailing how to drive safely in a roundabout is available on the PennDOT website.