ALL ABOUT ROUNDABOUTS

What Is A Roundabout?                   

*Click on the links below for more information/videos on Roundabouts in other states
http://www.iihs.org/video.aspx/info/roundabout
http://www.azdot.gov/CCPartnerships/roundabouts/index.asp
http://www.mnltap.umn.edu/Publications/videos/ModernRoundabouts/

A roundabout is a one-way circular intersection without traffic signal equipment in which traffic flows around a center island. Traffic maneuvers around the circle in a counterclockwise direction, and then turns right onto the desired street. All traffic yields to motorists in the roundabout and left-turn movements are eliminated. Unlike a signalized intersection, vehicles generally flow and merge through the roundabout from each approaching street without having to stop.

Benefits of Roundabouts

• Less Traffic Delays–Roundabouts carry more traffic with less delay than traditional signalized intersections. This operational benefit is the reason why roundabouts are considered in the first place.

• Safety–Roundabouts have been shown to reduce fatal accidents by as much as 90% and injury accidents as much as 75%, while pedestrian crashes reduced by 30-40%.The reduction in accidents is attributed to slower speeds and reduced number of conflict points.

• Reduction in Pollution and Fuel use–By yielding at the entry rather than stopping and waiting for a green light, travel delay is significantly reduced. A reduction in delay corresponds to a decrease in air pollution  and fuel consumption.

• Low Maintenance–Eliminates maintenance costs and electricity costs to approximately $5,000 per year. Service life of a roundabout is 25 years vs. 10 years for signal equipment.

• Aesthetics–The central island provides an opportunity for landscaping and beautifying of the intersection. Roundabouts provide a gateway and an entry treatment to neighborhoods.

Features of a Roundabout

• Yield-at-Entry–the entering traffic yields the right-of-way to the circulating traffic. This yield-at-entry rule keeps the traffic from locking up and allows free flow movement.

• Traffic Deflection–pavement markings and raised center islands direct traffic into the flow of the roundabout enabling the entering traffic to slow down which reinforces the yielding process.

• Flare–The entry to a roundabout often flares out from one or two lanes to two or three lanes at the yield line to provide increased capacity.

How to Drive a Roundabout

*Click here for general rules for driving a roundabout*

• Reduce your speed. Always keep to the right of the splitter island on the approach to the roundabout.

• Yield to traffic. Upon reaching the roundabout yield line, yield to traffic circulating from the left. Watch for traffic already in the roundabout, especially cyclists and motorcyclists.

• Emergency Vehicles. Do not enter a roundabout when an emergency vehicle is approaching on another leg; allow traffic to clear in front of the emergency vehicle.

• Do not stop. Within the roundabout, do not stop except to avoid a collision; you have the right-of-way over entering traffic. Always keep to the right of the central island and travel in a counterclockwise direction.

• Exiting the roundabout. Maintain a slow speed upon exiting the roundabout. Indicate your exit by using your right-turn signal. Watch for and yield to pedestrians and bicycles waiting to cross, or crossing the exit.

Pedestrian Crossings at Roundabouts

• Roundabouts generally are safer for pedestrians than traditional intersections. Crossing distances are relatively short, and traffic speeds are lower than at traditional intersections. In a roundabout, pedestrians walk on sidewalks around the perimeter of the circulatory roadway. If it is necessary for pedestrians to cross the roadway, they cross only one direction of traffic at a time using marked crosswalks, having a splitter island between lanes. As with any crosswalk no pedestrian may suddenly leave a curb or other place of safety and walk or run into the path of a vehicle that is so close as to constitute an immediate hazard. Look and listen for approaching traffic.

Bicylists Role in a Roundabout

• If you are riding on the shoulder or bike lane, merge into the traffic lane before the shoulder ends. Prepare for this move early, look over your shoulder, and signal your intent to move into traffic. Don't be intimidated; assert your position upon entering the roundabout.

• Once in the roundabout, don't hug the curb. Ride close to the middle of the lane to prevent cars from passing and cutting you off. Watch for cars waiting to enter the roundabout, as they may not see you.

• If you do not want to ride your bike in the roundabout, you may enter the sidewalk using the ramps, and proceed as a pedestrian.