Graph and Points courtesy of Washington State DOT http://www.wsdot.wa.gov/safety/roundabouts/benefits.htm

Graph and Points courtesy of Washington State DOT

Florida Roundabout Inventory – (click) Florida-Roundabouts-Inventory

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 collision.
  • Curious to know more? Watch a video about how roundabouts improve safety. 

see Federal Highway Administration March 2012 modern roundabout presentation at Purdue

and   > USA roundabout weblinks&videos at www.SarasotaConnectivity.com

and > Sarasota County web page https://www.scgov.net/PublicWorks/Pages/Roundabouts.aspx

Modern Roundabouts are NOT Traffic Circles or Rotaries

  • ROTARIES and CIRCLES terms do not apply to Sarasota’s modern roundabouts. Those are 1930s era obsolete intersection designs that today are being replaced with modern roundabouts in New Jersey (CIRCLES) and New England (ROTARIES).  Visitors and residents from those Northeastern states, hearing “roundabouts” think Sarasota is putting in the ROTARIES and CIRCLES they hate up there.  Sarasota’s “modern roundabouts” are today’s best-practice in managing intersections for safety, travel time, walkability, and biking.  A modern roundabout is the FDOT “preferred intersection alternative.”

Sarasota has two very old versions of CIRCLES: St. Armands Circle and the Tuttle/Siesta Drive Circle. Compare, modern roundabouts have no stop signs, much smaller centers, and no parking inside the roundabout.

TOURISTS, SENIORS, & DRIVERS HERE WILL NEVER GET IT. Studies report attitudes before and after roundabouts are installed shift from approx. 2/3 opposed “before” to approx. 3/4 “for” after the roundabouts have opened to users.  Seniors become advocates for more roundabouts because the traffic is moving the speed they want to go – SLOWER.   Tourists are more familiar with roundabouts than the locals, especially visitors from Europe.        

Why Build Roundabouts?
Roundabouts offer a sensible solution to safety and capacity problems at some intersections. Here’s a list of some of the benefits associated with modern roundabouts:

According to the Federal Highway Administration, installing a roundabout may result in:
A 76 percent reduction in injury-accidents
A 90 percent reduction in fatalities
75 percent fewer “conflict points” compared to standard intersections (see diagram below)
Major reduction in pedestrian injuries.                                                                       Conflict Points Diagram                                 diagram by Michael Wallwork, graphics by Ken Sides

Less Delay:
Roundabouts are designed to handle traffic more efficiently than signalized intersections. With traffic constantly moving and vehicles entering the intersection at lower speeds, more vehicles are able to move through the intersection at any given time.

An Improved Environment:
With more vehicles able to move through the intersection at any given time, there will be fewer vehicles idling for shorter periods of time. Because idling vehicles cause the most air pollution, roundabouts result in reduced air pollution.

Why do roundabouts have such a good safety record?

1. Conflicts are reduced. With fewer conflict points, roundabouts eliminate the potential for hazardous conflicts, such as right angle and left-turn head-on crashes.

2. Speeds are reduced and are more consistent. Low speeds in roundabouts allow drivers more time to react to potential conflicts, thus helping to improve the safety of roundabouts. Since most drivers travel at similar speeds through roundabouts, crash severity is reduced compared to traditional intersections.

3. Pedestrians cross one direction of traffic at a time. Pedestrians need only cross one direction of traffic at a time at each roundabout approach with “safe harbor” to pause in the median, not so at signalized intersections.

4. No red lights to run!  Police post video by red light camera. click Accident Sends Car Airborne: Caught on Tape  Red light cameras have not reduced red light running to zero.   Modern roundabouts do.

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