Roundabouts in Scottsdale
Modern roundabouts have been implemented in appropriate locations throughout Scottsdale. While many people in Scottsdale associate roundabouts with traffic calming, their real use--and benefit--is as a right of way control device in place of a traffic signal or multi-way stop. Studies in the United States have shown roundabouts to be significantly safer than traffic signals. In these studies roundabouts reduced collisions by approximately 30 to 50 percent, injuries by around 60 to 70 percent and fatalities between 80 and 90 percent when compared to traditional traffic signals. Roundabouts can also reduce delays, fuel use, emissions and maintenance costs. For these and other reasons roundabouts continue to increase in popularity as drivers become more familiar with them.
- Approach: Reduce your speed to the posted advisory speed. If it is a multi-lane roundabout, choose the appropriate lane for your desired destination based on the signs and markings. Yield to pedestrians in the crosswalk; THEY have the right-of-way.
- Enter: Yield to vehicles in the roundabout. Wait for a gap in traffic and merge into traffic in the roundabout to the right.
- Proceed: Continue through the roundabout until you reach your street.
- Avoid: Avoid stopping in the roundabout.
- Exit: Signal, then exit the roundabout to your RIGHT. Yield to pedestrians in the crosswalk.
- Approach: At the designated pedestrian crosswalk, look LEFT.
- Cross: Cross to the raised or painted splitter (see legend) or refuge island.
- Look RIGHT: Finish crossing to the opposite sidewalk.
More information on how to navigate multi-lane roundabouts, including an animated driving graphic, is available on our multi-lane roundabout page.
Scottsdale Roundabout Informational Video
To learn more about Scottsdale's roundabouts and how to navigate them, please view our video:
History of roundabouts in Scottsdale
Not all traffic circles are modern roundabouts. The City of Scottsdale began using circular intersections as an element of traffic calming projects in the mid 1980s. Developed before generally accepted modern roundabout guidelines were published, these designs lacked the now recommended splitter islands and larger central circles.
In 1986 a multilane roundabout was installed near the Princess Resort in1986. While slightly larger than what we would construct today, this roundabout incorporates many of the accepted modern roundabout guidelines and has had a very low collision history, averaging about one collision every two years.
In January 2014 a modern multi-lane roundabout opened at the intersection of Northsight Boulevard and Hayden Road as part of the Northsight extension project. Designed to give travelers an efficient option to bypass the busy intersection at Hayden Road and Frank Lloyd Wright Boulevard, the roundabout is the busiest in the city with approximately 35,000 vehicles going through it each day. It has reduced both injuries and travel times in the area.
Multi-lane roundabout intersections
- Hayden Road & Northsight Boulevard
- Princess Boulevard & Princess Drive
- 90th Street & Mustang Library Entrance
Single-lane roundabout intersections
- 60th Street & Dove Valley Road
- 64th Street & Lafayette Boulevar
- 68th Street & Cholla Street
- 70th Street & Oak Street
- 70th Street & Chaparral Road
- 74th Street and Sweetwater Boulevard
- 94th Street & Union Hills Boulevard
- 96th Street & Sweetwater Boulevard
- 96th Street & Cholla Street
- 100th Street & Cactus Road
- 104th Street & Cactus Road
- 104th Street & Cholla Street
- 108th Street & Cactus Road
- 124th Street & Columbine Drive
- 124th Street & Cactus Road
Modern roundabouts must meet a minimum of three criteria:
- All traffic must move counterclockwise around a raised, circular median. No traffic can travel through the center median.
- The roundabout must be designed to keep traffic between 15 and 25 miles per hour.
- All entering traffic must yield to traffic already in the roundabout. Besides yielding, no other type of traffic control, such as a light or stop sign, can control traffic in or entering the roundabout.
They are not the same thing. Compared to roundabouts, rotaries are often much larger, encourage higher traffic speeds, can route traffic through the center circle and sometimes use a combination of yield signs, traffic lights and stop signs to control traffic. Traffic circles, on the other hand, tend to be much smaller than roundabouts and are designed primarily to force slower traffic speeds in a neighborhood.
Because traffic must travel around a raised median, roundabouts eliminate head-on and right-angle (T-bone) crashes, generally the two most severe types of accidents. Furthermore, the design of modern roundabouts forces traffic to travel at speeds below 25 miles per hour. With conventional multi-stop and signalized intersections, traffic can still speed, another common element in the most severe crashes.
Because roundabouts permit the continuous flow of traffic, roundabouts typically result in reduced travel times.
While roundabouts encourage cars to travel at speeds of 15 to 25 miles per hour, the purposes of roundabouts are to improve safety, traffic flow and capacity at an intersection. Roundabouts are sometimes confused with traffic circles, whose primary purpose is to slow traffic in neighborhoods.
While it does cost more to construct a roundabout than a four-way stop, it costs about the same to construct roundabouts and signalized intersections. Roundabouts, however, tend to be cheaper over time than signalized intersections because roundabouts do not require electricity or maintenance of traffic lights.
While roundabouts require more space than a four-way stop, they take up about the same or often less space than a signalized intersection, particularly when left- or right-turn lanes are necessary.
With multi-stop and signalized intersections, traffic must sit and idle while it waits for its turn to go. With roundabouts, traffic often only needs to slow down and yield, rather than come to a complete stop. The avoided stop-and-go saves fuel, shortens travel times and reduces overall car emissions.
No. The capacity of a signalized intersection is typically much less than a roundabout, and the capacity of an all-way stop is half as much as a roundabout at best.
Roundabouts work best within a range of specific traffic volumes, ratios and patterns. When traffic volumes are too low, vehicles tend to travel at unsafe speeds through roundabouts. If traffic volumes are too high, particularly in one direction, then a signal is often necessary to allow cross traffic to enter the intersection. Finally, if intersections include three or more through lanes of traffic, a roundabout would likely confuse and frustrate many drivers.
- As you approach a roundabout, prepare to reduce your speed to 15 to 25 miles per hour. Road design and signage will encourage you and those around you to drive at a slow, uniform speed.
- As you approach a roundabout, slow down, look left and expect to stop. If there is no traffic in the roundabout or there is a wide enough gap between cars, however, a stop is not required. Most important, remember that you must yield to vehicles already in the roundabout.
- As you approach a double-lane roundabout, look for lane markings in the road, and choose the appropriate lane depending on where you want to go. Just like at a signalized intersection, don't expect to be able to turn left from a right turn lane.
- Don't change lanes in a multilane roundabout. If you need to exit and you find yourself in the inside lane, just go around the roundabout again. It will only add a few seconds to your trip.
City of Scottsdale - Transportation
7447 E. Indian School Rd., Suite 205
Scottsdale, AZ 85251