Q: It seems that wherever we go these days – shopping centers, new subdivisions, even well traveled routes that used to be straight lines – there are roundabouts, those goofy traffic circles that no one seems to know how to maneuver. Must be the new trend in traffic engineering. But it seems to me that these things are not helpful and, in fact, are confusing and harder to maneuver, and probably lead to more fender benders than the two-way or four-way stops they replace. Any figures available?
A: You’re right about the fact that the feds love them. Indeed, the Federal Highway Administration has information on its website proclaiming the virtues of roundabouts. I was unable to find any accident stats on roundabouts versus conventional intersections. But here’s what the FHWA says about roundabouts as replacements: “Angle and left-turn crashes at a typical four-leg intersection account for 63 percent of fatal crashes. Rear-end crashes are another type of crash often a problem at signalized intersections.”
Also, the feds point out, “right angle crashes are typically more severe because of the speed differential of the two vehicles … one vehicle is typically just starting to accelerate from a stop and the other vehicle going through the intersection at or above normal operating speeds. At a roundabout, vehicles are typically traveling at a significantly lower speed. Crashes that occur will be less severe because of this reduced speed differential and the more sideswipe nature of crashes.”
So there you have it.
No one seems to be suggesting that roundabouts eliminate accidents, or even that most folks have any idea what they’re supposed to do once they get into one. But at least as people maneuver them, doing the weave-and-duck bumper car routine, they’re going slowly enough that they tend to do less damage when there’s a collision.
By the way: It’s easy enough to do single-lane roundabouts: as you’re about to enter, you yield to the vehicles already in the circle and dip in when you can. Many have multiple lanes, however, and that’s where the dodge-and-dive routines come into play. Simple rule: when you dash into the circle, enter the lane you in which you intend stay. The Washington state Department of Transportation has an excellent graphic: wsdot.wa.gov/safety/roundabouts