Roundabout Information

Why Roundabouts?

In the correct location, roundabouts have been proven safer and more efficient than other types of intersections. Roundabouts provide lasting benefits and value in many ways and are often safer, less costly, and more aesthetically appealing than conventional intersection designs.

Safety

Studies have shown that roundabouts reduce injury crashes by 75% compared to stop signs and traffic signals. Studies by the Insurance Institute of Highway Safety and the Federal Highway Administration have shown that roundabouts typically achieve:

  • A 37% reduction in overall collisions
  • A 75% reduction in injury collisions
  • A 90% reduction in fatality collisions

There are several reasons why roundabouts help reduce the likelihood and severity of collisions:

  • Low travel speeds – Drivers must slow down and yield to traffic before entering a roundabout. Speeds in the roundabout are typically between 15 and 20 miles per hour. The few collisions that occur in roundabouts are typically minor and cause few injuries since they occur at such low speeds.
  • No light to beat – Roundabouts are designed to promote a continuous, circular flow of traffic. Drivers need only yield to traffic before entering a roundabout; if there is no traffic in the roundabout, drivers are not required to stop. Because traffic is constantly flowing through the intersection, drivers don’t have the incentive to speed up to try and "beat the light," like they might at a traditional intersection.
  • One-way travel – Roads entering a roundabout are gently curved to direct drivers into the intersection and help them travel counterclockwise around the roundabout. The curved roads and one-way travel around the roundabout eliminate the possibility for T-bone and head-on collisions.

Other Benefits

  • Less Vehicle Pollution – Roundabouts eliminate some stop-and-go traffic associated with stop sign or traffic lights. This leads to fewer vehicles idling while stopped at an intersection. Even in heavy traffic, vehicles continue to advance slowly in moving queues rather than coming to a complete stop.
  • Lower Maintenance Cost as Compared to Traffic Signals - A traffic signal requires electricity 24 hours a day. In addition, the signals need maintenance by field personnel for burned out lights, loop detector replacement, etc. A typical roundabout generally only needs electricity for streetlights at night.
  • Reduced Congestion – Yield signs reduce the number of vehicles that need to stop and also reduce the time vehicles are stopped.

Trucks and Farm Equipment

Roundabouts are designed to accommodate large trucks and farm equipment. The center of a roundabout has a Truck Apron which is raised and colored. It is intended to discourage regular vehicles from cutting through the roundabout, but is designed for trucks and farm equipment to assist in tight turns. 

Additional Resources