'Super circles' set drivers', traffic planners' minds spinning

Posted August 8, 2013

— With more people moving to the Triangle, area transportation planners are looking for ways to ease congestion with limited funding.

One idea being studied is a "super circle," which some consider a roundabout 2.0.

Roundabouts, such as those on Hillsborough Street in Raleigh and those being constructed on Chatham Street in Cary, require entering cars to yield to those already in the circle. Transportation engineers say they are generally more efficient and safer than intersections controlled by red lights because cars usually aren't stopped for long periods and are moving at a much slower speed.

Still, roundabouts draw mixed reviews from area drivers.

"I think, if you understand the rules and the process, it keeps the traffic flow consistent," driver Darin Sensabaugh said.

"To me, (drivers are) more likely to hit somebody than when it was straight through and you had to pay attention to the red lights," driver Dayle Conover said.

A "super circle" involves adding one stop light to a roundabout to control the number of vehicles entering during rush hours.

Planners eye 'super circles' to ease traffic congestion Planners eye 'super circles' to ease traffic congestion

"That would only operate during the peak hour or two when we need it, but the idea there is that signal on the one approach, when it turns red, it frees up space in the circle," said Joe Hummer, a former North Carolina State University professor who is now a traffic engineer at Wayne State University in Detroit.

Super circles are big in Australia, but Maryland and Florida are the only locales in the U.S. that have any, Hummer said. Triangle planners asked him to examine the idea, and he said they could replace some traditional intersections in the area.

"We didn't think a roundabout was possible, and now it will be," he said. "There's really lots of those (intersections) out there – one-lane streets or two-lane streets, the moderate volume."

Hummer acknowledged that American drivers generally haven't adapted to roundabouts, but he said he expects that will change as more drivers get used to them.

"It sounds like there's been an engineer hard at work that he's analyzed the situation pretty thoroughly," Sensabaugh said. "I could see where that would work out."


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  • Mon Account Aug 12, 2013

    I once saw someone stop, go in reverse, then take the exit off the traffic circle that they "missed".

  • MonkeyFace Aug 12, 2013

    There is a "roundabout" on Camp Lejeune, and its easy to figure out... BUT what I don't understand is this... why is there an inside lane? I mean really? Whats the point of getting in the inside lane to have to jump (or get stuck) into the outside lane in 5 feet to turn? lmao

  • Paul Parker Aug 9, 2013

    Today I finally figured out the roundabout. I came up to it and stopped completely...then after staring left with no one approaching from the left for about a minute I decided I could then go.
    Citizens Arrayest
    August 9, 2013 7:21 p.m.

    Citizens Arrayest is a perfect example of why roundabouts won't work here. Too many people have absolutely no concept of how to merge; they don't understand that they don't have to stop before merging, and they don't have any concept of how to accelerate to the speed of the traffic they are approaching in a merging situation so that they only have to modulate their speed very slightly one way or the other in order to merge with traffic.

  • Citizens Arrayest Aug 9, 2013

    Today I finally figured out the roundabout. I came up to it and stopped completely...then after staring left with no one approaching from the left for about a minute
    I decided I could then go.

  • whoami Aug 9, 2013

    We natives were doing just fine before the transplants came with their traffic circles and lack of courtesy.

  • DontVote4LiarsCheatsOrThieves Aug 9, 2013

    Thought Criminal WS - "Sorry but the only reason we have traffic congestion in this area is BAD DRIVERS. You can't fix stupid."

    Boy, you can say that again!!!

    There are some badly designed roads, but for the most part, it's stupid drivers, drunk drivers or drivers driving while on the cell talking or texting that cause the biggest problems here.

  • jcthai Aug 9, 2013

    dwntwnboy2, the roundabout on Hillsborough street isn't a true 2 land roundabout since it has lanes that you are supposed to stay in depending on which way you want to go. That roundabout is a joke, though because you don't have enough advance warning to allow you to see the signs, take in what they are saying, and then move to the appropriate lane.

    A true 2 lane roundabout is just that. 2 concentric lanes. If you are taking the next exit, you stay in the right lane. If you are going further, you get into the center lane. But what happens is somebody who doesn't understand, tries to go around in the right lane, and cuts off people trying to move back from the center lane to make their exit.

  • Thought Criminal WS Aug 9, 2013

    People in NC have enough trouble using turn signals, not texting while driving, moving from the left lane when driving well below the speed limit, and most are oblivious to the flow of traffic and other cars on the road.

    Anyone from Boston talking about how well the circles work need to explain how the I93/94/95 delays back up for 1-2 hours then.

    Sorry but the only reason we have traffic congestion in this area is BAD DRIVERS. You can't fix stupid.

  • Bartmeister Aug 9, 2013

    How any driver with any amount of time on the road can't figure that out amazes me and tells me we let people that shouldn't be on the road have a drivers license.


    Well hats off to ya. I ran into a dual lane roundabout for the first time ever in a roundabout and it was slightly confusing. I made it through, the signs wern't as clear as I thought it should have been. I came in at 6 o'clock and exited at 9 o'clock and had 2 turns to navigate past with blue hairs in between me and my turn all at 5 pm traffic in Northern Va. Those people were seriously intent on getting through the roundabout with or without me. I'd never seen one prior to it. I do like the concept though.

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