PennDOT finds roundabout way to improve intersection safety
PennDOT has found a roundabout way to reduce traffic collisions at intersections.
According to a study that included data from two traffic circles in York County, PennDOT found that the use of roundabouts reduced serious injuries by 76%. The conclusion came from the study of 33 intersections that were replaced with roundabouts.
“We continue to see that Pennsylvania’s roundabouts save lives and reduce crash severity,” said PennDOT Secretary Yassmin Gramian. “While they aren’t the right option in every intersection, we’re pleased that they help to make our roadways safer.”
American engineers have increasingly adopted roundabouts, which historically been more common in the rest of the world, as a means to ease traffic congestion, slow speeds and improve safety at key intersections. According to a database compiled by the the traffic engineering firm Kittelson & Associates, there were 8,800 roundabouts in the United States, as of last year.
Roundabouts are most often installed to address intersections with safety issues. Gramian said. They are also installed to improve traffic flow, calming traffic and allow pedestrian mobility to occur safely.
Two of the roundabouts studied were in York County, she said. One was along Route 116 (Main Street) and Hanover Street and Roths Church Road, which was opened in 2007, and the other along Route 74 (Delta Road) and Bryansville Road, which was opened in 2008.
The roundabouts were chosen because they had at least three years of data available before and after they were built. The data was based on police-submitted crash reports.
According to the report, a comparison of crashes before and after the installation of a roundabout showed:
- Suspected serious injuries were reduced by 76%
- Suspected minor injuries were reduced by 22%
- Possible/unknown severity injuries were reduced by 70%
- Total number of crashes decreased by 9%
There was one fatality reported after the installation of a roundabout among the 33 intersections studied, PennDOT reported. In comparison, there were three fatalities reported over the same period before the change.
In addition to the 36 roundabouts studied, 38 other roundabouts have been built on state routes that didn't have enough associated crash data to be included. Sixteen more are currently under construction, according to PennDOT, while another 15 are in the final design stages.
— Reach Anthony Maenza at email@example.com or @atmaenza on Twitter.