- June 10, 2009
While Sarasota is among the leading cities in Florida in incorporating roundabouts into its traffic management strategy, it has a long way to go to mirror Carmel, Indiana, when it comes to sending drivers around in circles.
With the completion of the U.S. 41-Gulfstream Avenue roundabout, Sarasota will have a total of 13 combined on city streets and the state highway. Carmel, meanwhile, has 142 roundabouts, the most of any city in the country. By 2025, the city of more than 100,000 people will have only one signalized intersection.
Dubbed the “roundabout capital of the U.S.,” compared to other Indiana cities with populations of at least 33,000, in 2020 Carmel had the fewest personal injury accidents in the state at 0.15% vs. the population. By contrast, Valparaiso and Evansville lead Indiana with 0.84% personal injury accidents vs. their population. According to the Insurance Institute for Highway Safety, Carmel has reduced by about 80% the number of injury accidents, and overall accidents by about 40%.
Injury accidents in roundabouts are lower than traditional signalized intersections because they all but eliminate high-speed crashes by significantly reducing conflict points with pedestrians and other vehicles. Every driver in the roundabout is traveling in the same direction, limiting crashes to the slower speed rear-end or sideswipe varieties. And although they keep vehicles flowing through the circle with fewer stops and idling, drivers must slow down to navigate the tight-circle movement.
“At its core the foundation of a roundabout is that it slows traffic down,” said Nina Venter, multimodal planner with the Sarasota/Manatee Metropolitan Planning Organization. “When you see a roundabout, it's sort of a cue that you need to slow your speed down to 15 to 20 miles an hour. When you get to modern roundabout, the first thing you encounter is a set of signs you need to follow to make sure you're in the right lane.
“Altogether, the geometry of the roundabout and the fact that it's a circle, the fact that it slows traffic down and the fact that you have all of these cues that you need to be sensitized to improves the overall safety of the intersection.”
According to the Institute for Highway Safety:
Commonplace in Europe and Australia, the first modern roundabouts in the U.S. were built in Nevada in 1990. They have been gaining in popularity here ever since, with some states such as New York and Virginia adopting “roundabout first” policies that require they be considered as a preferred alternative for new and upgraded intersections.
The IIHS research further found:
“Roundabouts at former signalized intersections change crash types from being head-on or T-bone collisions that are often are fatal in nature,” said Sarasota Chief Transportation Planner Alvimarie Corales. “We’re changing those to be angled and sideswiped, which reduces the crash severity and reduces he fatalities and serious injuries. I would say the average reduction in fatalities and serious injuries is 80%. By changing those crash heights we are improving safety at these intersections.”