The Pennsylvania Department of Transportation (PennDOT) announced that according to department data, fatalities, injuries, and crashes decreased overall after intersections were replaced with roundabouts. 

PennDOT reviewed data for 36 roundabouts on state routes at intersections that were previously stop or signal controlled. 

The roundabouts were selected based on having at least three years of crash data available before and after they were built. 

Department data from 2002 through 2021 shows the following: 

  • 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% 

Roundabouts are frequently installed to address intersections with safety issues but may also be installed to improve the overall flow of traffic. 

Further information on PennDOT's roundabout study can be found on their website