Roundabouts, in one form or another, have been “around” for hundreds of years, perhaps thousands of years (but probably not millions). For instance, you may recall your grandparents complaining about roundabouts whenever the circus came to town. No, wait, those were roustabouts…Oh man, how my grandfather dreaded those elephants (his house was downwind from the circus). In any case, your grandparents likely complained about roundabouts as well, and for good reason — roundabouts are not signalized! (Actually, there is one roundabout in Indiana that includes a traffic signal — sorry, my idea — more on that in a future article). But what this means is that all of a sudden, the decision to go/stop/yield is left up to the driver! Read that last statement again. Isn’t this going backwards in terms of the technological cool factor? Isn’t the goal to remove human beings from the traffic decision equation? After all, 94% of all accidents are due to what we in the business call, the human element. Airplane pilots figured this out decades ago (thus the expression, “auto-pilot”). Automobile drivers are just now figuring this out (thus the expression, “whoopsie”).
Let me be clear, roundabouts are not a bad idea. In the right location, under the right conditions, and (most importantly) when designed properly, they are magical. I am certain we are all aware of roundabouts that somehow vaporized traffic congestion. We no longer stop unnecessarily. We simply slow down and continue on our way. Amazing.
However, we are equally aware of roundabouts with confusing signage or pavement markings that seem to encourage unsafe maneuvers or reckless passing. Roundabouts must be intuitive; they must be easy. If it doesn’t make sense in an instant, people won’t like it, they will avoid it.
Single lane roundabouts are generally the most intuitive. Signage and pavement markings are largely an “assist” and seldom essential in terms of instructing drivers on what to do. Roundabouts containing more than one lane are a different story. To properly design a multi-lane roundabout requires an experienced traffic engineer — one who understands traffic engineering, human behavior and especially, the aging population. In other words, the most qualified traffic engineers are old guys. It takes experience and creativity to design an intuitive and safe multi-lane roundabout. Perhaps Leonardo Da Vinci said it best, “Simplicity is the ultimate sophistication.” And Dave Barry said it second best, “Never, under any circumstances, take a sleeping pill and a laxative on the same night.”
Roundabouts are here to stay. Granted, some may need a “redesign” as traffic patterns change and design philosophies improve, but they certainly have their place. Accidents at a roundabout tend to be nothing more than fend-benders — fatality rates go to zero.
Finally, it is worth mentioning, the decision to install a roundabout need not be a function of traffic volumes. This is quite different from signals or stop signs — both of these require specific traffic volumes. Roundabouts, on the other hand, may be placed anywhere, regardless of traffic volume. This is both a benefit and a temptation. Choose wisely.
Chet Skwarcan has over 25 years of traffic engineering experience and can be reached at Chet@TrafficEngineering.com.