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  • More "roundabouts", fewer intersections

    We have "roundabouts" and we need more of them just read this Insurance Institute link...

    http://www.connect2edmonton.ca/forum...newthread&f=30


    And a couple excerpts from other sources (links below):

    http://www.walkinginfo.org/pedsafe/c....cfm?CS_NUM=56

    "Of all the devices used in Seattle, traffic circles have proven to be the most effective at solving neighborhood concerns about speeding traffic and traffic accidents with a minimum of controversy. In addition, by slowing vehicle speeds, these devices make streets safer for pedestrians..."

    Results
    Between 1991 and 1994, ...The number of automobile accidents at these intersections fell 94 percent..."

    http://www.cityoflangford.ca/newsart...sp?TopicID=163

    A recent ICBC study shows that traffic circles are 80 per cent effective in reducing traffic accidents.
    Accidents in traffic circles tend to be the less severe sideswipes rather than the deadly T-bone type
    that occur at stop signs and signals. A similar study in the USA on roundabouts found a 39% reduction in vehicle accidents, a 76% reduction in injury accidents and a 90% reduction in accidents causing death or permanent incapacity. A traffic circle is really just a small roundabout.

    There are only 8 conflict points in a traffic circle compared to 32 in a four way stop condition.

    Reduced Delay: ...This is true under non-peak traffic conditions and especially evident at high traffic flows.

    Environmental Benefits:..."

  • #2
    I agree. I'd love to see more of them in neighbourhoods, but even possibly roundabout interchanges like this: http://www.cbrd.co.uk/reference/inte...undabout.shtml
    City Centre Airport is to the sky as False Creek is to the ocean.

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    • #3
      I disagree - I don't think they have much advantage over a 4 way stop. While they can work in certain locations, once traffic volumes reach a threshold quantity, they can result in horrible traffic jams if you for example, have traffic entering from South and West only at rush hour, mainly going East, then South will be trapped. When you add in the horrible accident rate at traffic circles in Edmonton, they aren't worth the effort.

      The biggest traffic jams I have been in, in my life (not in Edmonton), have been a result of traffic circles. They are only for low volumes (which a 4 way stop can service), or locations where there is equal quantity of traffic from all directions at all times (and there aren't many locations like that).

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      • #4
        I'm a huge believer in traffic circles. There's two busy ones within a few blocks of our house and they effectively move traffic. Most of the accidents I see are rear enders due to someone braking to let a pedestrian cross and the car behind not paying attention.

        The key is that drivers need to know how to use them. That's often not the case.

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        • #5
          i agree. they make it safer. they alsy reduce the need for lights and make streets and neighbourhoods prettier with well maintained and landscaped islands of green/ public art in the middle.

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          • #6
            I think traffic circles are best in residential neighbourhoods, especially where there is a lot of through traffic. We need cars to use the arterial and collector roads in the city.

            Hopefully, over time, we can phase some traffic circles out, especially 107 Avenue/142 Street and 118 Avenue/St. Albert Trail. Bonnie Doon might be here to stay.

            Until then, perhaps having a sign showing "Get in the Inner Circle" or some other message to that effect to encourage proper use of traffic circles.
            "Talk minus action equals zero." - Joe Keithley, D. O. A.

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            • #7
              I agree on the issue of backing up traffic if one side gets cut out of the action. However, I wonder what they do differently in Europe. Or do they use the best tool for the job.

              On one vacation, during off peak hours, I've drove through a real 'monster' of a roundabout near London and wondered how on earth it worked in rush hour. I think they took the concept too far in that particular instance. Maybe dogmatism (i.e applying the same solution to all problems) reigns in transportation department's everywhere.

              Regarding the 107Ave /142St circle - wouldn't a third - right hand turn "free flow" lane work? Currently, the traffic light a block to the west by the church serves to interrupt the traffic - allowing north bound 142nd street traffic the opportunity to continue on. Maybe short cycle traffic lights on all sides a block or two back, would actually work in concert - creating the best of both worlds.
              Last edited by KC; 11-11-2008, 04:01 PM.

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              • #8
                Originally posted by KC View Post
                Regarding the 107Ave /142St circle - wouldn't a third - right hand turn "free flow" lane work?
                You mean the left lane for 3/4 and 1/2 turns, the middle lane for 1/2 and 1/4 turns, and the curb side lane for 1/4 turns only?

                or

                You mean the left lane for 3/4 turns only, the middle lane for 1/2 turns only, and the curb side lane for 1/4 turns only?

                Comment


                • #9
                  Regarding the free flow lane: Either way - which ever worked best. Currently, the left lane can legally make a 1/4 turn to the right - that couldn't be allowed any more as that permission would have to be reserved for the new "middle" lane. The first option would offer some progress during rush hours assuming those in the free flow lane would be able to merge left once around the corner and down the road. It wouldn't do anything for the backed up original lanes. So, it's probably not a great solution.

                  I think traffic lights / cross walk lights interrupting the flow of the dominant rush hour lane is a better solution. Before you say - "Well that's a standard intersection!" Think about this. Place some short cycle red lights situated back from the roundabout itself would only need to be operated for maybe two hours a day - during peak hours - for the other 22 hours of every day they could be left green to allow the traffic to flow efficiently and unimpeded.

                  Such lights, like cross-walk lights could create the necessary breaks in traffic flow to allow the backed up perpendicular traffic flows an opportunity to proceed, be easily adjusted for duration, and may only be needed on one or two sides, etc.

                  Anyway, just thinking on the fly here but it seems that this approach might be a lot cheaper (in costs and accidents) than full fledged intersections with coordinated 4 way intersection lights.


                  Lux's Roundabout Interchange link is fascinating. Lately we seem to have preferred building overpasses with stop lights and left turns up on top of them, where you still have have to make a left to go right. It looks like the Roundabout Interchanges' eliminate the lights and probably for much of the day - the stop and go - replacing it with a yield and go and less risk of being t-boned.
                  Last edited by KC; 11-11-2008, 04:39 PM. Reason: Clicked on lux's link above.

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                  • #10
                    Although there are rules about using roundabouts, a degree of courtesy from drivers is an imiportant factor. From what I see daily in Edmonton, courtesy is in pretty short supply and the lack thereof probably led to the situation that exists now in having traffic lights on some roundabouts in this city. That said, the Bonnie Doon one seems to work okay.
                    Nisi Dominus Frustra

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                    • #11
                      Roundabouts work great, one thing that the city could do to make them more user friendly would be to put up signs saying which exit leads to where. For example

                      Mike

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                      • #12
                        Roundabouts are like any other device on the road, when people know how to use them, great, if not, they're lousy.

                        As for pedestrian safety, that one isn't a given, either. I walk the cricle at the top of Groat Hill / 87th ave all the time, and I've seen lots of people just fly through the crosswalks when people are waiting to cross, and a couple times while they were crossing. Talk about "missed it by that much!"

                        Comment


                        • #13
                          Originally posted by The_Cat View Post
                          Until then, perhaps having a sign showing "Get in the Inner Circle" or some other message to that effect to encourage proper use of traffic circles.
                          From the Gov AB Basic License Drivers' Handbook (p.73)
                          "Remember these safety tips:
                          • Enter into the right-hand lane of a traffic circle when you intend to leave
                          at the first available exit point.
                          • If you are planning to proceed to the second exit or beyond, it is
                          recommended that you use the left-hand lane.
                          • When entering or leaving a traffic circle be aware there may be marked
                          pedestrian crosswalks."

                          "Safety tip" is to use the inner lane, not law.
                          Traffic circles can create massive headaches when commuting during rush hour and drivers insist on using only the one lane. Defeats the purpose of this free-flow traffic instrument.
                          You can never have too much garlic

                          Comment


                          • #14
                            Originally posted by incubo nero View Post
                            Originally posted by The_Cat View Post
                            Until then, perhaps having a sign showing "Get in the Inner Circle" or some other message to that effect to encourage proper use of traffic circles.
                            From the Gov AB Basic License Drivers' Handbook (p.73)
                            "Remember these safety tips:
                            • Enter into the right-hand lane of a traffic circle when you intend to leave
                            at the first available exit point.
                            • If you are planning to proceed to the second exit or beyond, it is
                            recommended that you use the left-hand lane.
                            • When entering or leaving a traffic circle be aware there may be marked
                            pedestrian crosswalks."

                            "Safety tip" is to use the inner lane, not law.
                            Traffic circles can create massive headaches when commuting during rush hour and drivers insist on using only the one lane. Defeats the purpose of this free-flow traffic instrument.
                            And here, folks, is the dumbest thing directly under provincial control to do with traffic circle use and safety. You can't have "friendly suggestions from the Province" when legal control is required instead.

                            There is one way around this; in a couple of places, they put up a sign telling you to enter from a certain lane for a certain exit. In this case, the sign takes precedence over the standard rules (or lack of rules) for traffic circles.

                            Oh wait, they don't enforce anything on the roads in this city anyway.
                            City Centre Airport is to the sky as False Creek is to the ocean.

                            Comment


                            • #15
                              use the right lane (outside) for 1/4 or 1/2 and use the left lane (inside) for 1/2 or 3/4 (or 4/4 if you forgot your turn a few blocks before the traffic circle). Right lane always yields to left lane. Its just that simple. Don't know how others can't get it. Get it?
                              A people that elect corrupt politicians, imposters, thieves and traitors are not victims, but accomplices.

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