State: Traffic Roundabouts Lower Injuries, Deaths

HARRISBURG PA – Traffic roundabouts like that built at the intersection of Routes 29 and 73 in Lower Frederick Township (above), or the one being contemplated for Swamp Pike and the Arcadia at Limerick Pointe project in Limerick Township, help reduce the incidence of crashes, injuries, and fatalities once they are installed, according to Pennsylvania Department of Transportation statistics reported Thursday (Sept. 27, 2018).

“Our data shows that modern-day roundabouts reduce crash severity and injuries while improving traffic flow,” PennDOT Secretary Leslie S. Richards said, claiming round-abouts are “becoming more common in Pennsylvania and beyond.”

The agency reported it recently looked at information on 11 roundabouts on state routes at intersections that were previously stop- or signal-controlled, reviewed primarily because each had at least three years of data available before and after their installations. Department data, based on police-submitted crash reports spanning the 7-year period between 2000 and 2017, shows:

  • Fatalities were lowered 100 percent (from two to none);
  • Serious injuries were reduced 100 percent (from seven to none);
  • Minor injuries were reduced 95 percent (from 19 to one);
  • Possible or unknown severity injuries were reduced 92 percent (from 49 to four);
  • Crashes causing only property damage declined 2 percent (from 49 to 48); and
  • The total number of crashes dropped 47 percent (from 101 to 54).

A total of 43 roundabouts have been installed on state routes, including the Lower Frederick circle – built during 2009 at a cost of $800,000 – that was part of PennDOT’s review. Twenty-six others are in design stages, including the Limerick circle that is proposed to control traffic on Swamp Pike near its intersection with West Ridge Pike.

Sanatoga-based Traffic Planning and Design Inc. provided transportation planning and engineering services for the Lower Frederick installation, as well as for the proposed roundabout in Limerick.

Roundabouts are frequently installed to address intersections with safety issues. They also may be appropriate, PennDOT said, to improve traffic flow, heighten traffic calming, and facilitate pedestrian mobility.

Although safer and typically more efficient than traditional intersections with traffic signals, in many cases roundabouts may not be the best option due to topography, property impacts, capacity issues and proximity to other intersections.

Photo from Google Images