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Transportation Government United States News

Roundabout Revolution Sweeping US 1173

chrb writes "BBC News reports that U.S. cities are installing more roundabouts than ever before. The first British-style roundabout appeared in the U.S. in 1990, and now some cities — such as Carmel in Indiana, are rapidly replacing intersections with roundabouts. Supporters claim that roundabouts result in increased traffic flow, reductions in both the severity and incidence of accidents, and fuel savings. Critics say that roundabouts are more difficult to navigate for unfamiliar American drivers, lead to higher taxes and accidents, and require everyday acts of spontaneous co-operation and yielding to others — acts that are 'un-American.'" As a driver who's hit all of the continental U.S. states except North Dakota, I dread roundabouts and rotaries for all the near accidents (and at least one actual accident) I've seen them inspire, and have been unhappy to see them spread. Spontaneous driver cooperation doesn't necessarily need the round shape, either.
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Roundabout Revolution Sweeping US

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  • Really bad idea. (Score:4, Interesting)

    by yog ( 19073 ) * on Monday July 04, 2011 @11:13AM (#36652362) Homepage Journal
    Roundabouts (or rotaries, or traffic circles, as they're known in parts of the U.S.) induce confusion and fear in many drivers, although they can be useful at times. This article [] from an insurance periodical suggests that it's aggressive drivers who are making rotaries more dangerous.

    I like rotaries for two reasons: when there's no traffic, it's nicer than having to stop at an arbitrary red light and wait for a mandatory 2 minutes while the lights cycle. Secondly, if I am not sure whether to turn or not, I can just take another spin around the circle until I see the street sign I'm looking for (assuming there is one, not a given on some of the sign-challenged Northeast roads).

    But I loathe rotaries when there's a lot of traffic. You can sit there for a lot longer than you would at a red light. Plus, some places make a rotary out of a 5-way intersection which can be incredibly confusing. It's a tradeoff, I guess, but overall I'd rather drive in a straight line :)
  • Re:Really bad idea. (Score:4, Interesting)

    by tepples ( 727027 ) <tepples@gmail.BOHRcom minus physicist> on Monday July 04, 2011 @11:17AM (#36652404) Homepage Journal

    But I loathe rotaries when there's a lot of traffic. You can sit there for a lot longer than you would at a red light.

    I don't see why it would be any longer than a four-way stop. And it'd be an improvement over a couple intersections in Fort Wayne, Indiana, that don't detect a bicycle parked directly over the crack in the road where the vehicle sensor loop is buried. I sometimes have to wait eight minutes for a truck to pull up behind me and trip the vehicle sensor so that my lane gets a green light.

  • Re:Really bad idea. (Score:5, Interesting)

    by Anonymous Coward on Monday July 04, 2011 @11:23AM (#36652470)

    Most places have exemptions for bicycles and motorbikes at intersections for these reasons. Basically, the law says that you treat the red light as a stop sign and proceed when it's safe. You should check your local laws.

  • Re:Really bad idea. (Score:5, Interesting)

    by Joce640k ( 829181 ) on Monday July 04, 2011 @11:31AM (#36652610) Homepage

    When you get the hang of roundabouts we'll teach you how to use these: []

  • Re:Sweet Lord No (Score:2, Interesting)

    by digitrev ( 989335 ) <> on Monday July 04, 2011 @11:38AM (#36652712) Homepage
    I hate to reply to myself, but I thought I should mention one the single best uses of a roundabout I've ever seen. If one travels from Highway 417 in Eastern Ontario and heads south on March Road (I say this so people can look at a map if they'd like), it's a blindingly boring stretch of road. Mostly straight, a bit hilly, and lends itself quite amiably to speeding like an idiot. I've accidentally gone as much as 40 km/h over the speed limit (or about 20 km/h more than I was aiming for). This is fine for the country road, but eventually you get to the small town of Almonte, where the traffic picks up considerably.

    In the past, I suspect this resulted in maniacs speeding through town, on their way to the next destination. However, by use of a roundabout, they forcibly slow people on their way in, putting them in a much better frame of mind for the town, without bringing traffic to a complete halt, and likely resulting in collisions from people running the stop sign.

    Not only that, but the idiots who are likely to try and speed through anyways get themselves into trouble before entering the town and endangering the residents. I though that this was a genius little piece of civil engineering, and if I ever meet the man who thought of it, I'd gladly buy him a round.
  • by Idarubicin ( 579475 ) on Monday July 04, 2011 @11:41AM (#36652760) Journal
    While I fear this may be an (emotionally) unpopular assertion here on Slashdot, could it be that pool of U.S. drivers is inherently less-skilled than drivers in many other developed countries? Yes, yes--I know that you (whomever you might be, dear American who is reading this comment right now) are a superb, attentive, alert, efficient, far-above-average driver, but for a moment consider just how stupid and inconsiderate all those other yahoos you have to deal with on the road are.

    The fact is, it's harder to get a driver's license in a lot of other countries. The standards and expectations are higher. In the U.S., I exaggerate only very slightly to suggest that a driver's license (and even automobile ownership) are seen as a fundamental human right, rather than a privilege. Most places, public transit is something that poor people use until they work hard enough to live the American dream (with accompanying house in the 'burbs and two-car garage).

    Many other driving nations impose stricter conditions on new drivers, graduated licensing schemes (which require the passages of time and/or tests before new drivers are allowed greater driving privileges--the use of high-speed highways, driving late at night, driving without another experienced driver, etc. may all be prohibited to new drivers), older minimum driving ages, and more complex driving tests than the United States.

    Despite its abundant roundabouts, the UK enjoys a non-motorway death rate about 15% below that of the U.S. [] (Their motorway death rate is more than 60% less, but that's pretty much irrelevant to the roundabout issue.) Better public transit also means that people who can't or shouldn't be driving are less tempted to do so.

  • by DontBlameCanada ( 1325547 ) on Monday July 04, 2011 @11:41AM (#36652770)

    My first experience with roundabouts was during a vacation to Australia (Brisbane). They are absolutely everywhere and once I'd gotten used to the etiquette in play, I fell in love with them. I drove from Brisbane all the way north to a little resort where we were catching a chart to snorkle the Reef. Traffic never really stops, folks on the roundabout have the right-of-way, but the pace is deliberately slow so that merges on and off and controlled and traffic continues to flow.

    You *cannot* run a red light or miss a traffic signal as the intersection usually has a garden or statue *right in the middle of traffic*. If you are somehow so inattentive or drunk entering the intersection that you miss the big wall in front of you, folks on the roundabout have plenty of time to recognize that you aren't going to stop as you *are* in their field of vision as they travel on the circle. They can either stop or take evasive action as you smash into the concrete barricade. Drivers are empowered and required to remain attentive, even when they have the right-of-way. As you need to make a tight circle while on the traffic circle, you *must* drop speed or you'll never make the turn. Accidents on a traffic circle tend to be low-speed with minor or no injuries.

    A standard traffic light abdicates all responsibility to a device. Vehicles traveling in a straight line through an intersection tend to do so at or above the speed limit - so pedestrian and driver error is frequently catastrophic or fatal. I don't know about others, but I'll take an increase in fender-benders to avoid head-on or t-bone accidents. [] has some excellent information about roundabouts. Note in point 5:
          "5 What are the common types of crashes at roundabouts? What can be done to prevent them?

            Despite the demonstrated safety benefits of roundabouts, some crashes still occur. Fewer crashes are typically seen at single-lane roundabouts compared with multilane roundabouts.5

            An Institute study of crashes at 38 roundabouts in Maryland found that four crash types (run-off-road, rear-end, sideswipe, and entering-circulating) accounted for almost all crashes. A common crash type at both single-lane and double-lane roundabouts involved vehicles colliding with the central island. These crashes, which often involved unsafe speeds, accounted for almost half of all single-vehicle run-off-road crashes. Collisions occurred more frequently at entrances to roundabouts rather than within the circulatory roadway or at exits. About three-quarters of the crashes involved property damage. There were no right-angle or head-on collisions, potentially severe crash types that commonly occur at traditional intersections.6

            In the Maryland study, Institute researchers concluded that unsafe speeds were an important crash factor. Some drivers may not have seen the roundabout in time. Measures to alert drivers of the need to reduce speeds (e.g., speed limit signs well in advance of roundabouts) and increase the conspicuity of roundabouts (e.g., larger roundabout ahead signs and YIELD signs, enhanced landscaping of center islands, pavement with reflector markings) may help to reduce crashes at roundabouts. Certain design features such as adequate curvature of approach roads also may aid in reducing speeds."

  • Re:Really bad idea. (Score:2, Interesting)

    by Anonymous Coward on Monday July 04, 2011 @11:42AM (#36652790)

    We have had round-abouts here in Australia for well over 20 years and people still don't know how to use them properly. It is especially dangerous for pedestrians who cannot tell if a car is going to keep going around the round-about or if they are going to turn off.

    Regarding accidents, it seems that most accidents on round-abouts these days seem to be single vehicle accidents where someone has lost control of their vehicle going around the round-about (some people think that its quite safe to treat them like a chicane and not really slow down for them) or they don't notice the round about and end up hitting the rail on the centre of the roundabout.

    All in all, I believe they reduce the risk of fatal accidents but do cause more non-fatal ones (there are probably some statistics floating around but I cba looking them up...)

  • by Mathieu Lutfy ( 69 ) on Monday July 04, 2011 @11:48AM (#36652880) Homepage

    A few places in Montreal use round-abouts with zebra crossings for pedestrians, with a small sign that says "100$ fine if you do not give priority to pedestrians". While there are always exceptions, it works pretty well.

    Cars drive a bit slower, but given that they don't have long lights to wait for, it is generally faster. Win-win.

    (which is a bit surprising, since Montreal is probably one of the worst cities in North America with regards to respecting road signs, by either motorists, cyclists or pedestrians, but my impression is that when removing road clutter, people kind of start thinking again)

  • by Khomar ( 529552 ) on Monday July 04, 2011 @12:02PM (#36653054) Journal

    One of the big pitfalls for roundabouts that I saw in Montana when they tried to implement them was not taking into account snow removal (at big deal in Bozeman, MT) and emergency vehicles. They placed large concrete islands in the middle of the intersection, and there was not enough room for the larger vehicles to navigate around it. The snow plows couldn't even see the island after a big storm and would run right over it.

    They are not the end-all solution, but in certain circumstances, I can see where they would be beneficial.

  • by Andy_R ( 114137 ) on Monday July 04, 2011 @12:08PM (#36653130) Homepage Journal

    The thing I find puzzling about the American resistance to roundabouts is that they actually contain no new concepts at all, you don't have to 'learn' anything to use them. Topologically, they are just a one way street with T-junctions.

    Ever pulled out of a side street into one-way traffic? That's exactly what you do when you join a roundabout. Even turned off a one way street into a side street? That's exactly what you do when you leave.

    To answer your question, have you ever walked along a main street and crossed a side street that didn't have traffic lights? That's exactly what you do when you cross at a roundabout.

  • by david.given ( 6740 ) <> on Monday July 04, 2011 @12:10PM (#36653140) Homepage Journal

    Usually, they just cross --- I live in Reading, UK, and it's full of roundabouts that work like this. There's usually an island between the two lanes just as the road enters the roundabout; partly this is acts as a spreader to split the lanes and make the junctions easier to manage for cars, but as a side effect it gives pedestrians somewhere to stop in the middle, so they only have to cross one lane at a time.

    When I started to drive I hated roundabouts; there were too many places to look and I couldn't track all the inputs needed to negotiate them safely. Once I got used to them, I really like them. They scale beautifully to the level of traffic and varying number of exits and can keep the traffic moving smoothly up to quite heavy loads. On really heavy traffic there's various tricks you can do to keep them working well: one cunning one is the use of spiral lanes. In this variant, as you approach the roundabout you move into the correct lane for your destination, merge onto the roundabout and follow your lane straight into the appropriate exit.

    They're particularly good on motorway exits; a common approach is to have an elevated roundabout above the motorway, with sliproads connecting roundabout exits to the motorway. You can leave the motorway, merge onto the roundabout, and then it becomes trivial to select your exit either to a minor road or back onto the motorway in either direction.

    They don't work well when the traffic isn't evenly distributed; imagine a four-exit roundabout with heavy traffic moving east-west and you want to get on to the roundabout from the south. You'll end up spending quite some time waiting for a gap, because you have to give way to the traffic that's already on the roundabout. If there's traffic coming from the north, it all works properly; they enter the roundabout, force the east-west traffic to stop to give way to them, which creates a gap that you can move out into.

    They completely fail when you put lights on them. Once that happens, all the elegant traffic management falls apart completely and you end up with complicated, frustrating multistage junctions. There's one terrible roundabout in Reading (at Winnersh Triangle; locals will know it) where not only have they put lights on it but in a desperate attempt to solve the traffic problems have actually put a road straight across the middle. Years of tuning have reduced the irritation level to merely annoying, but it's still a poor junction. But then, there isn't really such a thing as a good junction at that level of traffic.

    Right now the Reading council has a thing about replacing small, effective roundabouts with lights. Everyone is screaming high heaven about it. One set of lights they just put in (Shinfield Road) has pretty much doubled my commute time, due to lousy design, failure to do the research, delays, and generally Not Being A Roundabout.

  • Re:Really bad idea. (Score:5, Interesting)

    by sifi ( 170630 ) on Monday July 04, 2011 @12:12PM (#36653174)
    That roundabout is genius - it's so confusing that everyone drives really carefully and there are probably less serious accidents there than 'normal' roundabout.
  • Re:Really bad idea. (Score:4, Interesting)

    by billcopc ( 196330 ) <> on Monday July 04, 2011 @12:14PM (#36653190) Homepage

    DISCLAIMER: I am not a city engineer, but I've spent far too much spare time researching these issues.

    They take longer for two main reasons: in heavy traffic, a full roundabout is either constantly moving, or dead stopped like a parking lot. In either case, you can't get in because everyone is bumper-to-bumper.

    The heavy traffic scenario is where city planners fail hard, because they too easily forget that roundabouts still shuffle the same number of vehicles into the same congested streets. If these get backed up, so does the roundabout.

    There are, fundamentally, three solutions to traffic, and nobody wants to implement them:

    a. less cars
    b. more lanes
    c. less concentration in commercial and industrial sectors

    Solution A requires vastly improved public transit, for which no city official wants to shoulder the cost, or more telework which employers are still reluctant to undertake. Solution B requires expropriation to make room, and often leads to complicated entry/exit ramps, and all that costs a shitload of money. Solution C depends on Solution A, so we're doubly screwed.

  • Re:Really bad idea. (Score:5, Interesting)

    by Heed00 ( 1473203 ) on Monday July 04, 2011 @12:39PM (#36653500)

    Two factors are important: Build them large enough, so traffic flowing in has a chance to anticipate an open spot. And make people aware of how they work. Tell it on the radio, in TV spots and so on.

    Exactly. These are two important points. Canada is also adopting the roundabout in some areas and the size is a real issue as many are so small that you might as well just put a 4-way stop or traffic lights in because the traffic just backs up in all four directions anyway -- the roundabout is too small to allow the traffic to keep flowing and merging. On the point of education, I received a flyer in the mail at the beginning of the year providing instructions on how to properly use a roundabout. You can see the website it pointed to here: []

    The interesting thing for me was that I had been in England since 2000 and only returned back to my native Canada in 2010 to suddenly see roundabouts as part of the roadways. My first reaction was, "But almost nobody would have taken a driving test that would include roundabout protocol" -- this was painfully obvious when I saw the "seat of the pants" approach many took to coming upon a roundabout. I'm now back in England and actually kept the flyer I received to show to the locals here -- I have rarely seen such laughter upon reading a pamphlet.

    I'm guessing, but I would wager roundabouts are cheaper to implement than the other traffic flow solutions -- the authorities like to talk about safety, improved traffic flow etc. but when you put in a new element on the roadways with minimal education and build it on an ineffective scale, then that makes me think that cost is the driving factor.

  • Re:Way before 1990 (Score:4, Interesting)

    by molnarcs ( 675885 ) <> on Monday July 04, 2011 @01:14PM (#36653820) Homepage Journal

    Washington DC has rotaries [], not roundabouts [].

    How about reading your own link:

    "Traffic circle" is a term mainly used in the United States to describe a junction which in other countries would be called a roundabout.


  • Re:Really bad idea. (Score:5, Interesting)

    by R3d M3rcury ( 871886 ) on Monday July 04, 2011 @01:25PM (#36653904) Journal

    Actually, it is not LEGAL to ride a bicycle on the sidewalk [...]

    Depends on where you live.

    Here in California, riding on the sidewalk may be legal depending on where you live. It is not decided at the state level. So, for example, it may illegal to ride your bike on sidewalk in San Francisco but perfectly legal to ride your bike on the sidewalk in Garden Grove. It might be legal to ride on the sidewalks of Newport Beach, but not the ones on Main Street.

  • Re:Really bad idea. (Score:4, Interesting)

    by Cederic ( 9623 ) on Monday July 04, 2011 @01:40PM (#36654036) Journal

    Doesn't placing traffic lights on roundabouts defeat the purpose?

    There are roundabouts that only have certain entrances/exits traffic lighted - that assures a primary route doesn't clog it, without forcing other routes to wait for a green light if there's a gap.

    There are also roundabouts that have "peak time" traffic lights. When the flow of traffic is at its heaviest (when roundabouts become less optimal) the lights switch on and work much as lights anywhere do, but at other times you get the benefits and convenience of a roundabout.

    they install them in little-used residential streets. It means no traffic to bother with, but it also means I have to navigate a silly turn instead of going straight

    This is why we use mini-roundabouts which are usually a painted circle on the road (with maybe a convex tarmac circle that peaks at less than the height of the kerb). The rules of the road are exactly as for a roundabout, but if it's clear you just drive straight over the centre of it.

    Those work extremely well..

  • Re:Really bad idea. (Score:4, Interesting)

    by Space cowboy ( 13680 ) on Monday July 04, 2011 @02:51PM (#36654640) Journal

    Yes, well the UK driving test is actually worth something. I had to do a hill start, 3 point turn, right-hand reverse, parallel parking, different speeds of driving, turning out of a blind intersection, roundabouts, emergency stop, and probably more that I don't remember.

    In the US, I turned right out of the DMV onto a 30mph road, turned first right, turned first right, turned first right, turned first right, and then turned back into the DMV. I had already passed the "written" part of the test (really, multiple choice. One question was 'what does this sign mean?'. It was a STOP sign...). That was it. Apparently that's all you need to drive one of the massive honking SUV's they have out here at 100^W 65(hah!) mph on the freeway. It does explain a lot about the (apallingly-bad) standards of driving out here though. The Italians are better drivers. As someone who's lived in Rome, I really mean that...

    Oh and for the record, I far prefer roundabouts to 4-way intersections. They're really pretty simple, guys... To be fair, that's probably more because that's what I started with, but still, to hear yanks talk about them, you'd think they were the spawn of Satan or something.


If I had only known, I would have been a locksmith. -- Albert Einstein