Roundabouts are the intersections of choice for safety
I have written at least a half-dozen of these articles touting the benefits of roundabouts, especially the safety factor. Still, in the five-county area of New York State Department of Transportation Region 7 (Lewis, Jefferson, St. Lawrence, Franklin and Clinton), which has a population of 375,000 to 380,000, there are only four: two in Champlain, one in Plattsburgh and one in Massena.
Yet, Carmel, Indiana, a city of about 92,000 north of Indianapolis, has about 125 roundabouts with another 30 or so planned. The Villages, Florida, with a population of around 122,000, has 36 as I write this article. In all of New York state, the total number of roundabouts is approximately the same as in Carmel, Indiana.
So why are other areas in the U.S. installing so many roundabouts compared with New York state and especially upstate New York? I can’t answer this, but I’m sure DOT has its marching orders, which I believe is to consider a roundabout whenever making significant changes to any intersection on state highways. But roundabouts aren’t the answer in every case.
Physical restrictions must be considered (roundabouts need more area than do traditional intersections with traffic signals), obstacles such as culverts may be a limiting factor, and initial cost must be considered. Also, for pedestrians with disabilities, especially the visually impaired, roundabouts may be less desirable than a traditional intersection. In the design of a highway several competing needs all must be taken into account in determining the most appropriate option.
But when it comes to traffic flow that’s safer, faster and cheaper, roundabouts are often the answer. The 36 roundabouts in The Villages are touted by engineers as smart replacements to crash-plagued stop sign intersections or congested traffic signal intersections. European drivers in places like France are 25 times more likely to find a roundabout intersection than a traditional one with stop signs and traffic signals.
“The Villages was really on the forefront of their implementation,” said Amber Gartner, a transportation engineer with Kimley-Horn, an urban planner used by The Villages. Roundabouts are safer because they have only eight “conflict points” compared to 32 for traditional intersections, she explained in an article in The Villages Daily Sun newspaper.
Safety is the top factor in their popularity, said Sumter County Administrator Bradley Arnold. “Typical accidents (crashes) at signalized intersections are either T-bone or head-on,” he said. “In roundabouts most crashes are side-swipe crashes, which are less likely to result in a fatality.”
Lower speeds and the lack of left turns in roundabouts cut fatalities by 90% and crashes with injuries by 75% from other types of intersection traffic controls, according to the Florida DOT and the Federal Highway Administration as reported in the newspaper article. There are also 35% fewer crashes in general in roundabouts, per the U.S. DOT. These figures are in line with everything I have studied relative to the safety of roundabouts.
Next week’s article will discuss the experience of The Villages, Florida, and Carmel, Indiana, and how roundabouts there have significantly reduced traffic crashes.