The Outstater

August 19, 2022

Squaring the Roundabout

THE ROUNDABOUT, a traffic design to control intersections, is being used more frequently here these days. Yes, they are stylish. Paris has had roundabouts for a long time but they were originally incorporated into the city’s spoke-and-wheel street design so that Napoleon could better position his cannons to level any crowds of unhappy citizens — a different but not unrelated matter.

For roundabouts still have a political element if not a military one. Some see them as a microcosm of how government works — or doesn’t.

The recent death of U.S. Rep. Jackie Walorski and three others in a head-on crash at a rural roundabout on State Road 19 near Nappanee has focused public attention. Some great reporting by our friend Margaret Menge raised questions about whether the daylight accident in good weather with a competent driver was the result of the roundabout design or at least confusion stemming from the design.

Now, sloppy policy doesn’t usually kill people (at least at the local level) but when it does it is rarely a member of Congress. The sensational nature of the accident and the details in Menge’s article argue to me that the Walorski crash deserves a closer look.

Nobody but nobody in officialdom sees it that way. The incentives all run toward treating the roundabout as an inarguable good, not a congresswoman-killer. The reason for that we will get to in a moment, but first know that we cannot turn to any independent authority other than the Indiana Department of Transportation (INDOT), which, as all such departments, is politically captured and won’t be raising serious questions.

What, for starters, are roundabouts meant to accomplish? Their claim to smoothing the flow of traffic is suspect, depending as it does not only on an optimum traffic load but from equal directions in specific time ranges. Besides, the heavy work in traffic flow was done some time ago with improvements in road surfaces, tires, brakes, transmissions and the internal combustion engine.

Nor does improved safety hold up to a common-sense review. If you apply game theory to the context of an intersection you realize that safety will be affected by complexity, the number of options a driver must navigate to avoid a crash. In a four-way stop or a traffic light, the options are just three— the stop, the go and the always tricky left turn. But if all the players get those right, things go well.

Not so with a roundabout and its confusing lane and yield directions. Once in a roundabout, the danger is constant and real of edging into the wrong lane at any time, being unyielding when you should be yielding, crossing what you do not recognize to be a center line, all of which is multiplied and complicated by others who may be entering the roundabout simultaneously and from surprising directions, negotiating the same options with greater or lesser skill and confidence. Consider this explanation from an Indianapolis traffic engineering firm:

“Runabouts are circular intersections, but not all circular intersections are roundabouts. Roundabouts generally have an outside diameter of 100–200 feet while traffic circles, also called rotories, may have outside diameters of 500–1,000 feet. On a roundabout, the circulating traffic on the circle has the right-of-way, and the approaches must yield to circulating traffic. On traffic circles, the traditional right of way rule for unsigned intersections applied so the circulating traffic had to yield to the traffic trying to enter, which filled up the circular roadway while reducing the exiting capacity. In modern roundabouts the exiting traffic has the right-of-way over vehicles trying to enter and only yields to pedestrians in the crosswalk.”

Got that? And they call that safer?

So why are roundabouts or traffic circles considered a motorist’s Godsend, such an inarguable good? Because a roundabout can cost as much as two million dollars, that’s why, excluding engineering, the purchase of additional right-of-way and utility relocation — twice as much as even a signaled intersection with turn lanes.

And that, dear friends, is blood in the water, new money, for those who hang around meetings of the State Budget Committee. For doubling the dollars of any line item instantly creates a new rent-seeking industry, complete with its own team of legislators, department heads and as much rationale and media support as money can buy.

Roundabouts don’t cost, they save, you have been told, the more the better. Anyone who questions that will be buried in piles of data collected by — you guessed it — those who have a vested interest in roundabouts or their agents. There is no competing lobby or independent research for cheap and arguably safer four-way stops and traffic lights.

And those who would protect the motorist’s interests at INDOT or in the pertinent legislative committees have other things on their minds such as perfecting society, expanding departmental budgets and who is going to get elected for what — different kinds of roundabouts entirely. — tcl



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