Roundabouts

The 5th Street roundabout opened in 2009, and has been running smoothly ever since. The City of Lynchburg is looking to build more throughout the city for a number of reasons outlined below. This page will hopefully answer many questions you may have on roundabouts. 

What is a roundabout?

A roundabout is a type of street intersection where traffic must travel in one direction around a central island.  Roundabouts are often confused with traffic circles, but vary in four important ways. 

  1. The center island is generally smaller in diameter, requiring slower travel speeds
  2. Traffic entering the roundabout must yield to the traffic already in the roundabout.  This keeps traffic from locking up and allows a free flow movement
  3. Splitter islands deflect entering traffic and reinforce the yielding process
  4. Pedestrians are prohibited from entering the central island, keeping traffic within the roundabout in continuous motion.

What are the benefits?

Safety. Roundabouts are widely accepted as one of the safest types of intersection design, reducing fatal and injury crashes as much as 75%. When crashes do occur they are generally less severe. This is because roundabouts reduce the number of conflict points (points where traffic paths cross) from 32 down to only 8. The 8 conflict points that are left would generally only be side-swipe crashes as opposed to head-on collisions.

Capacity. Roundabouts can handle 30-50% more traffic than a traditional intersection and has fewer delays.

Economic. While the capital investment in roundabouts is similar to a traditional intersection, operational and maintenance dollars are significantly lower, reducing the financial burden on taxpayers. The savings can be significant over the long term when a traditional intersection can cost a locality $5,000 per year in maintenance and electricity and replacing the Virginia Baptist Hospital traffic signal on Rivermont Avenue cost $97,585. A roundabout does not require signals and would not sustain damage requiring repair of that magnitude.

Environmental. Reduced traffic delays and leads to a decrease in fuel consumption and air pollution.

Aesthetic. The central island provides an opportunity to beautify the intersection with landscaping and public art, while also helping create memorable places in the city.

Kingsport, TN  

 

 

  Newport News, VA

What about trucks?

The City wouldn’t build roundabouts if truck traffic could not easily navigate them.  Modern Roundabouts like the ones we are building contain a “truck apron” to allow the inside wheels of large trucks to have extra turning space.

Video from the Kansas Department of Transportation:
Are large trucks able to navigate a roundabout?

What about pedestrians?

While pedestrians may not be as safe as they are in a traditional intersection with highly visible crosswalks and where all vehicles stop to allow a pedestrian to cross, roundabouts strike a balance between pedestrians and vehicles.  Roundabouts provide splitter islands where pedestrians can cross the street one lane at a time and traffic in roundabouts naturally develop timed breaks allowing pedestrians to cross safely.

 Nantucket, MA

What about bikers?

Bikers may have the toughest time with roundabouts.  Roundabouts on bike corridors should be designed to allow bikers to exit the roadway and enter a large path shared with pedestrians before entering a roundabout.