Another Roundabout Gets Ok

Studies show safety, traffic flow advantages


The Payson Council on Thursday approved the idea of a two-lane roundabout at the intersection of Airport Road and Highway 87, after four years of waffling and 40 minutes of debate.

The Arizona Department of Transportation came to the town for approval of the design of a roundabout, with the understanding the town would pay about $390,000 of the $1.2 million cost.

Two ADOT traffic engineers and the head of the town's own traffic advisory committee joined forces to convince the long-dubious town council that roundabouts move more traffic, more safely than stoplights.

But despite testimony by one resident that most people she talked to opposed another highway roundabout, the council's major concern was whether the roundabout should have two lanes for highway traffic or should narrow down to a pedestrian-friendly one lane in each direction.

The roundabout debate headlined a long, but amiable town council meeting marked by the flourish of proclamations, good natured council banter and unanimous votes. It was the next to last meeting for the outgoing council members -- Bob Edwards, Andy Romance and Tim Fruth.

In addition to approving ADOT's roundabout design, the council moved efficiently through a host of issues, including.

  • Rejected a proposed $90,000 remodel of the Main Street fire station, citing a budget crisis brought on by a plunge in sales tax and building permit fees.
  • Approved a revision of the water conservation ordinance that locked in water-saving measures regardless of annual rainfall.
  • Adopted a fence ordinance designed to avoid unsightly fences and to prevent fences from blocking the view of drivers.
  • Approved the final plan for a condominium subdivision on Tyler Parkway, after a vigorous discussion about how to make sure the heavily loaded construction trucks don't tear up the streets.
  • Approved a preliminary plan for a five-lot subdivision on Chaparral Pines Drive, after asking the owner to move a street to save an Indian ruin.

The highway roundabout stirred the most public interest and triggered a debate that pitted Councilor Romance against the ADOT engineers. Romance pushed hard to convince ADOT to at least experiment with a roundabout design that would funnel highway traffic into a single roundabout lane, which would allow side street traffic to move into the circle more easily and pose a less daunting barrier for pedestrians.

Tom Loeffler, a retired state highway administrator and head of the town's Surface Transportation Advisory Committee (STAC), carried the day for roundabouts at the outset by reeling off a list of statistics on the intersection control approach that is sweeping the country - with outposts in Sedona and Prescott.

Among the statistics Loeffler cited:

A single lane of traffic can carry 1,800 cars per hour without backups, but installation of a signal reduces that capacity to 800 cars per hour. A second signal on the same stretch would reduce the flow to 500 cars per hour.

A one-lane roundabout can move the same 1,800 cars an hour through an intersection as a single lane with no intersections.

Cars entering an intersection with a signal have 32 "conflict points" where an accident can happen. Cars entering a roundabout have just 8 conflict points.

A 2007 study of 55 intersections converted from a signal to an roundabout documented a 35 percent drop in total accidents and a 75 percent drop in fatal accidents.

Not a single driver or pedestrian has so far died in a U.S. roundabout intersection.

The Institute of Highway Safety estimates that roundabouts reduce pedestrian accidents by 75 percent.

Maintaining a stoplight costs $6,000 annually.

The councilors all declared their support for roundabouts, but questioned the design and lack of landscaping.

Town Engineer LaRon Garrett noted that the town would have to pay for any landscaping.

But most of the council questions centered on whether the roundabout would make it easier for residents to get onto and across the highway, even when the summer visitor crush puts about 15,000 cars per day on the highway.

Fruth asked if ADOT could lower the speed limit from 40 to 35 approaching the roundabout. However, ADOT's roundabout experts who attended the meeting said the state would only change the speed limit if a traffic study showed that on average more than 15 percent of drivers exceeded the current 40 mile per hour speed.

"Otherwise, you're just creating a speed trap," said ADOT Engineer Randy Blake. He noted that the current limits are based on repeated traffic studies.

Councilor Mike Vogel said he supported the roundabout, but that "you guys have done a lousy job of teaching people how to use roundabouts," he said. "They see a ‘yield' sign and they don't have a clue."

Moreover, he said that police have to watch out for kids having roundabout contests - with one recent incident setting a record of 67 laps around the roundabout before they "got run off."

But Fruth noted that anything would be an improvement. "People can't cross the street at all now. We've left this for four years and it's still sitting here in a pretty significant intersection where accidents have occurred."

Romance pushed hard to get ADOT to use traffic islands to funnel approaching highway traffic into a single lane, as Sedona has done in several cases. The one-lane roundabout would make it much easier for cars from the side streets to merge onto the highway - and for people to cross.

But the ADOT engineer said that would reduce the carrying capacity of the roundabout by 50 percent. He conceded that the one-lane Sedona roundabout carries 20,000 cars a day, but said a one-lane roundabout here could not accommodate future traffic growth without causing backups during peak periods.

"I understand ADOT's need for a high capacity Beeline Highway, but please understand Payson's need for pedestrian safety and lower speeds," said Romance.

The council eventually approved the ADOT design, with the question of the type and cost of landscaping left for later.

ADOT will now hold public hearings on the plan and could actually build the long discussed roundabout next year.

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