In western Pennsylvania and throughout the state, roundabouts are becoming more common due to inherent advantages of increased safety and reduced delay.
Roundabouts have fewer conflict points and encourage lower speeds. Based on observed performance at signalized intersections, roundabouts experience a 90% reduction in fatal crashes, 75% fewer injury-causing crashes, a 30-40% reduction in pedestrian crashes, and a 10% reduction in bicycle crashes. These reductions are due to the elimination of most head-on, left-turn, and right-angle crashes.
Roundabouts can carry 30% more vehicles than similarly-sized signalized intersections during peak traffic conditions. Increased capacity at roundabouts is due to more free flowing traffic, yielding only until a gap is available instead of waiting at a signal. During off-peak conditions, roundabouts cause almost no delay, while traffic signals still cause delay to side-street and left-turning traffic.
Explore the links to learn more about how roundabouts will operate within our project area, understand more about how roundabouts work, and see how PennDOT District 12 has incorporated roundabouts in other local projects.