Numbers Don’t Lie: Roundabouts and Intersection Safety at Home and Abroad

Jan 24, 2020 | Firm News

When two alternative plans for the redevelopment of the three westernmost intersections of Fruitville Road were released in February, some people said the plan was insane. On a road where four lanes have consistently created traffic backups and a number of accidents over the years, critics say that it seems counterintuitive to reduce the road to two lanes and install roundabouts instead of lights. However, in a number of reports from around the world where roundabouts have been installed, including the roundabouts in Sarasota, they have largely proven to move traffic more efficiently, elevate safety, and reduce accidents.

Because a roundabout involves only right turns, it makes better use of the intersection, allowing many cars to use the intersection at a time, instead of only one or two (like a standard intersection with a light or a stop sign). The theory was even tested on the television show Mythbusters, which proved that roundabouts were over 20% more efficient than four-way stop signs. Considering the traffic stacking that occurs at four-way stop lights, roundabouts also allow for constantly moving (although much slower) traffic instead of the growing impatience that comes with sitting in a non-moving car.

Across the board, properly-designed roundabouts do cut down on accidents. As the American Association of State Highway Transportation Officials’ Highway Safety Manual reports, “roundabouts REDUCE the types of crashes where people are seriously hurt or killed by 78-82% when compared to conventional stop-controlled and signalized intersections.” A 1996 German study of 34 roundabouts showed a decrease in severe injuries from 18 to 2, and accidents with heavy property damage decreased from 24 to 3. A 1986 study of 83 roundabouts in France saw accident fatalities reduced by 88% and injuries down by 78%, while a 1988 study of 522 roundabouts found that 90% of the accidents resulted in no injuries.

As early as 1981, Australia did a before-and-after study of 73 roundabouts in which they measured a 74% reduction in accidents resulting in casualties and a 32% reduction in accidents resulting in property damage. Since then, Melbourne alone has developed over 4,000 roundabouts, but they are not always safer. As a matter of fact, for bicyclists in Australia, roundabouts can be especially hazardous.

One of the things that makes roundabouts safer is their design to slow traffic down. However, this only occurs when they are developed in a radial design, like those employed in the UK, in which the driver cannot see what is around the corner and must reduce speed to maneuver safely. Many of the roundabouts in Australia are developed using a tangential design in which drivers don’t really have to slow down to enter the roundabout. The result is that approximately 1 in every 10 accidents in roundabouts in Victoria involves a bicycle, and in Melbourne, it’s reported that half of all roundabout crashes from 2004 and 2009 involved cyclists.

The state of Washington began installing roundabouts in 1997, and of the 120 they have since installed, the Washington State Department of Transportation reports a 37% reduction in overall collisions, a 75% reduction in injury collisions, a 90% reduction in fatality collisions, and a 40% reduction in pedestrian collisions. Switzerland also reports a 75% reduction in total accidents and 90% reduction in injuries at two of their roundabouts. However, none of those places is Sarasota.

Although roundabouts have been largely proven to reduce injuries and expedite traffic when built correctly, many Sarasota drivers say that they are just too confusing. Since Sarasota County installed its largest traffic circle in Venice five years ago, the intersection, featuring a two lane roundabout, has earned the distinction of having the most accidents in the entire county. Fortunately, there have been no fatalities at the intersection since the overly confusing roundabout was installed, and the next most accident-prone roundabout at Honore Avenue and Webber Street isn’t even in the top 20 worst intersections countywide.

Nevertheless, the roundabouts implemented in the downtown area (on Main/Orange, Five Points, Ringling/Pineapple, and Ringling/Palm) have proven to move traffic quite fluidly, and accidents have been reduced. The City of Sarasota currently has plans for 16 more roundabouts to be installed by 2023, 10 of them along US-41 from University Boulevard to downtown Sarasota. While they may be challenging for Sarasotans to get used to, it seems that the implementation of properly-designed roundabouts will make Sarasota traffic run more smoothly and be safer for drivers and pedestrians. Bicyclists, however, may need to continue riding with caution.