47 ms·

Safety benefits of roundabouts

• tpmx 3y ago
  Seriously, americans need to learn about these.
  • seabird 3y ago
    We have plenty of them. They're usually pretty miserable because your average American driver is a fucking moron and they're best not deployed unless there's a safety reason to do so.
  • spogbiper 3y ago
    we have tons of them where i live in south florida
    • eesmith 3y ago
      There are differences between a modern roundabout and the broader category of circular junction. The De Soto Plaza in in Coral Gables, FL, built in 1925, as seen at https://www.google.com/maps/@25.7450124,-80.275242,3a,75y,75.83h,88.51t/data=!3m6!1e1!3m4!1sK2JbGSKQ6f1O9BDRq4mzqA!2e0!7i16384!8i8192?entry=ttu https://www.google.com/maps/@25.7450124,-80.275242,3a,75y,75... is not a modern roundabout. Granada Blvd does not indicate a yield-to-enter, while the others streets have stop signs. I think that one should also have splitter islands. (Video of its history at https://archive.org/details/Did_You_Know_-_DeSoto_Plaza_Fountain https://archive.org/details/Did_You_Know_-_DeSoto_Plaza_Foun... .) I think Cocoplum Circle might count as a roundabout? https://www.google.com/maps/@25.7059315,-80.2608362,3a,75y,193.27h,78.34t/data=!3m6!1e1!3m4!1sanOfSMCXwFUwiK_7T8X8IQ!2e0!7i16384!8i8192?entry=ttu https://www.google.com/maps/@25.7059315,-80.2608362,3a,75y,1... There are also "traffic calming circles", which are not roundabouts. "Traffic calming circles should not be confused with roundabouts, which are designed to handle much higher traffic volumes and reduce vehicle delay." - https://www.sfbetterstreets.org/find-project-types/pedestrian-safety-and-traffic-calming/traffic-calming-overview/traffic-circles/ https://www.sfbetterstreets.org/find-project-types/pedestria...
  • Minor49er 3y ago
    As an American, I can assure you that we have loads of these
    • desas 3y ago
      As a guy who actually read the article, I can assure everyone else that this American is right > In 2000, the U.S. only had 356 roundabouts. Over the past two decades, that number has grown to over 10,000.
      • Y-bar 3y ago
        Less than half the 25,000 in UK, or just over half the 19,000 in Italy, or almost matching the 15,000 in Spain. It's great news all over that the number is clearly increasing, but still a very long long way to go until it becomes widespread.
        • oblio 3y ago
          To put things into perspective: 65 million + 60 million + 45 milion = 170 million people, about half of the US population. So 59 000 roundabouts for half the population versus 10 000 in the US. That's a deficit of 90% per capita :-)
        • csdreamer7 3y ago
          Indeed, wasn't until 2011 or so until I saw my first roundabout in the USA. For my other Americans, read the Australian's post above. Can get across an entire town without stopping as a reason to remake our towns with roundabouts.
      • candiddevmike 3y ago
        My area, and a lot of others I think, are no longer building stop light intersections. Everything new is a roundabout.
    • deleted 3y ago
      [deleted]
    • 3y ago
  • parshimers 3y ago
    the resistance is a problem. there are a few in Pasadena, CA on Los Robles between California and Raymond where it's a roundabout, with stop signs on each entrance. the worst of both worlds.
• grecy 3y ago
  I grew up in a town in Australia nicknamed "The City of Roundabouts". Essentially all intersections in the entire town are roundabouts, including two lane ones, etc. It's quite common to drive the entire length of town (~20 blocks) in reasonably heavy traffic without ever stopping. On a good day you do it in 2nd gear, the whole way. At night you can do it in 3rd gear, because it's exceptionally easy to see headlights of any car you need to yield to. Four way stops do not exist (I've never seen one in all of Australia), and they are still the strangest concept for me living in Canada. They feel like a colossal waste of time and energy, and vastly worse than roundabouts.
  • simondotau 3y ago
    In my two decades of driving I’ve seen one 4-way stop in Australia. The intersection of Dickson Avenue and Clarendon Street, Artarmon NSW. Haven’t seen one anywhere else.
    • eesmith 3y ago
      Street View - https://www.google.com/maps/@-33.8160242,151.1838978,3a,75y,106.62h,70.85t/data=!3m6!1e1!3m4!1sMbfvaeCEtG3Q_UsaqZTEoQ!2e0!7i16384!8i8192?entry=ttu https://www.google.com/maps/@-33.8160242,151.1838978,3a,75y,... Apparently there was one in Rockingham, Western Australia, says https://www.news.com.au/technology/innovation/motoring/fourway-stop-sign-stumps-wa-motorists-brings-traffic-to-a-standstill/news-story/1ef6f0332c199c409a454acf2de9ebe7 https://www.news.com.au/technology/innovation/motoring/fourw... ("Four-way stop sign stumps WA motorists, brings traffic to a standstill") but it is not there now at https://www.google.com/maps/@-32.2753035,115.7324187,3a,75y,12.29h,84.05t/data=!3m6!1e1!3m4!1s6tKpDm4HP8vcYktOyGFk8Q!2e0!7i16384!8i8192?entry=ttu https://www.google.com/maps/@-32.2753035,115.7324187,3a,75y,... .
    • beej71 3y ago
      As someone from the US, I find this quite overly entertaining. "Find the one 4-way stop on the continent!" They're so common in the US that 3-way or 2-way stops are often marked as such so that you don't make any assumptions about cross traffic stopping. And please don't misunderstand me--I'm definitely envious.
• squarefoot 3y ago
  Safety aside, roundabouts lower traffic significantly by never forcing cars to stop. Congestion increases as cars need to stop because of the inevitable latency propagating along the tails, and having more than one traditional intersections along the way can only make things even worse, so any solution to prevent cars from slowing down to a stop would mitigate those effects.
  • sokoloff 3y ago
    Until you do what Cambridge, MA has done twice near my house: put a traffic light just outside the roundabout, so when the light turns red, traffic inevitably backs up through the roundabout, locking it up entirely. https://www.google.com/maps/@42.3875777,-71.1422076,18z?entry=ttu https://www.google.com/maps/@42.3875777,-71.1422076,18z?entr...
    • timc3 3y ago
      They do that in Sweden all the time. I have no idea how a country that has some amazing minds can come up with the worst road infrastructure designs possible. Most of it’s unsafe so they just lower the speed limit.
    • securingsincity 3y ago
      I used to drive over there quite a bit. Always terrible.
    • foobarian 3y ago
      The circles of death? :-)
    • lumb63 3y ago
      I can decisively say anyone advocating for roundabouts has not lived anywhere near Boston.
      • InSteady 3y ago
        Let's be real, is this actually an indictment of roundabouts or is it just Boston?
• calimoro78 3y ago
  My experience is that roundabouts help but don't solve. E.g. if there is a complete traffic jam, you may actually increase the risk of collision due to negotiations about right of way happening every time a car can move forward. Some cities in Europe have so many roundabouts, and two or three lane roundabouts with complex exit decisions you need to make on a split second - it's actually very confusing to navigate.
  • oblio 3y ago
    That's not the main point, though. They decrease serious collisions.
  • dfxm12 3y ago
    You're never going to "solve" traffic problems when people are driving cars, but when you look at the data, crashes that lead to injuries and, importantly, fatalities, go down with roundabouts. and two or three lane roundabouts with complex exit decisions you need to make on a split second - it's actually very confusing to navigate. I think you're confusing what today might be called a "rotary" (?) with a modern roundabout. Whatever you call it, I don't think anyone builds what you're describing anymore.
    • giantg2 3y ago
      I've seen 2 lane roundabouts brand new in the US.
      • JohnFen 3y ago
        Same in my part of the US. They're the most common kind, and new ones are constantly being constructed.
  • giantg2 3y ago
    "My experience is that roundabouts help but don't solve" Because they don't remove the idiots from the roads. The same people who willfully ignore right of way at stops signs also ignore right of way in the roundabout.
• rwmj 3y ago
  If you like roundabouts, try a roundabout of roundabouts: https://en.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hempstead) https://en.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hempst... This is near where I live and it is indeed safe, mainly because everyone drives incredibly slowly and cautiously since the experience is scary as hell.
  • marginalia_nu 3y ago
    Using roundabouts of roundabouts it's actually possible to build a 3 dimensional roundabout where traffic along the x, y and z axis can safely meet on the surface of a sphere.
    • Arrath 3y ago
      Please, the average driver has trouble enough merging into traffic.
      • marginalia_nu 3y ago
        Well, when you mention it, I do think it's possible to join these 3d roundabouts into a 4d roundabout, essentially putting them on the vertices of a tesseract, permitting drivers in 4 dimensional space to safely meet on the 3d-dimensional surface of a 4-dimensional hyper-sphere. Of course it's a real spaghetti intersection where you need to potentially navigate dozens of 2D roundabouts to get to any given direction. Which coincidentally also is true for the 2D road network where I live.
        • Arrath 3y ago
          "And that, kids, is the story of how I T-boned myself."
          • marginalia_nu 3y ago
            Now you're thinking with portals!
• osullish 3y ago
  I’m from rural Ireland, and I always remember my first roundabout - I used go driving with my dad when learning, and as the weeks progressed I’d get closer and closer to Killarney which was the nearest town. Coming from our side the first thing you meet is a roundabout with 3 exits, one bringing you out the roads that bypass the town, one to the town centre, and one to a housing estate off the roundabout. As I joined the roundabout I met a woman driving against me on the roundabout taking a shortcut to her exit of the housing estate - frightened the shit outta 16 year old me, my dad was spooked too. I managed to make room enough for her to pass - she was oblivious. My dad actually knew her, lived there all her life, she must have driven that road 1000 times - how often was she taking that shortcut
• loosescrews 3y ago
  I'm not a traffic engineer, but I think roundabouts take more space than an equivalent signal or stop sign intersection. The article says that many places are starting to default to roundabouts, but many intersections are likely going to be difficult to upgrade.
  • graywh 3y ago
    if roundabouts are already common and drivers behave, a mini roundabout can work but if they aren't common, so you need to construct it in a way that requires compliance, more space is required
• mattlondon 3y ago
  Obligatory reference to this: https://en.m.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hempstead) https://en.m.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hemp... Roundabout with more roundabouts on it. Because. Basically just a little ring road.
• gnicholas 3y ago
  Interesting that there are no listed downsides. I saw a more balanced article a while back and recall that it listed cost (especially of the additional real estate, since roundabouts are larger) as being one downside. And in built-up cities, it's basically impossible to convert traditional intersections to roundabouts, because there's simply no room. It is nice to not have to pay for replacement signals, or have to deal with power outages that kill the signals though.
  • ceejayoz 3y ago
    Cost is probably not a downside when you consider the cost of accidents.
  • polemic 3y ago
    Roundabouts are great (and common where I live), but a downside is they can be difficult for pedestrians to cross. You need crossings that are set back from the exits, but this also makes it a longer path for the pedestrian.
    • timc3 3y ago
      Tunnels and bridges are used in the UK. And those tunnels are horrible.
    • cluoma 3y ago
      This is certainly an issue. There is a roundabout on my morning commute that regularly has pedestrians crossing inside the roundabout (alongside cars on the outside) because that's the most direct route.
    • swatcoder 3y ago
      Yes, they're absolutely horrid for pedestrians. Drivers anticipating their merge into roundabout are often too distracted to notice pedestrians intending to cross, and any pedestrian crossing the outflow of a roundabout can trigger a traffic backup that interferes with the flow of the circle itself and surprise drivers who expect it to stay moving. They have their benefits in some intersections, but they also have tradeoffs that make them very poor for others.
• hristov 3y ago
  The greatest thing about roundabouts is that they protect against the idiot that goes through an intersection at full speed. He does that either because he is passed out behind the wheel or because he did not notice a stop sign and thought he had the right of way, or maybe because he just does not care. Well with a roundabout if you just go straight ahead you hit the center circle. Good roundabouts always have a slight hill and some kind of barrier (a tree or some kind of statue) in the center so that the guy that just goes straight through will hit something in the center and wont come out the other side and will thus be less likely to kill an innocent person. Single lane roundabouts are usually a good idea if the cost justifies it. Double and more lane roundabouts probably should be avoided in the US; they include rather obscure rules as to which lane you are allowed to drive in at any moment and americans do not like to learn new rules.
  • Jtsummers 3y ago
    As long as that center circle is high enough. I had a woman in a Toyota (Camry?) fly over one at about 45+mph and slam into me as I looped around it. Totaled her car, broke parts off my Explorer (repairable). Her son then tried to attack me with my bumper. She kept insisting I turned in front of her (technically true, I was in a roundabout). She was arrested for drunk driving, and, later on, fined for all the flowers she damaged in the circle and the median she also ran over on her way into the intersection.
    • hristov 3y ago
      Sorry to hear about that. But the roundabout probably soaked up some of her speed at least.
    • lukas099 3y ago
      Was there any kind of barrier within the circle besides flowers?
      • Jtsummers 3y ago
        The curb she flew over and some brick paving stones used as the perimeter of the little garden, which was enough to stop non-drunk drivers, but no wall or anything.
• zabzonk 3y ago
  safety? bah! try going round the hanger lane gyratory system (west london, uk) in a triumph spitfire, at high speed, driven by a girl (my girlfriend at the time) who was too tiny to reach the pedals.
• gniv 3y ago
  Here in France they have both types of roundabouts, yield-to-left-on-entry and yield-to-right. They are well signaled, so there is no confusion. The latter type is less common and seems to be mostly in less-busy areas. I'm not sure why they still use them though. Is it because you have better visibility to the right, since you're already in the intersection? It's an interesting design choice.
  • giantg2 3y ago
    I dislike the yield to right. They're rare here, but I believe that's how some of the traffic circles are in NJ.
  • giraffe_lady 3y ago
    I think the yield-to-right ones are primarily a traffic calming thing, where the threat to yield limits how fast you can comfortably go through them. They use a lot of yield-to-right intersections in residential areas with poor visibility for the same reason. It's conceptually similar to the 4-way stops on low-traffic streets in the US, just streamlined and formalized.
  • hermitcrab 3y ago
    >there is no confusion Maybe not if you grow up with it. But there certainly is if you are a British tourist, used to always giving way to the right.
• a_e_k 3y ago
  Personally, I'm fine with the simple single-lane roundabouts. They're convenient for U-turns, for example. For anything above that where I have to cross lanes to get to the center circle and then cross lanes again to get back out and exit, I'd rather just have a conventional traffic light-controlled intersection. (I try to minimize lane changes when I drive.)
  • stvltvs 3y ago
    > I try to minimize lane changes when I drive. Same here, but by the end of a recent trip to Iceland, two lane roundabouts were easy-peasy. The learning curve is short in my experience.
• _zamorano_ 3y ago
  In Spain we use roundabouts heavily. They're perfect for crossings with low to middle traffic. No useless waiting time, good visiblity and no need for traffic lights. For heavy traffic, though, they're useless as the car flow of one entry/exit can take over the roundabout and block all other entries. Also, it seems hard to understand for many drivers that regulations regarding changing lanes don't change in a roundabout. So more than 3 lanes are not advisable in my opinion.
  • throw0101a 3y ago
    > For heavy traffic, though, they're useless as the car flow of one entry/exit can take over the roundabout and block all other entries. Not wrong, but traffic lights can be added to roundabouts as well ("signalized roundabouts") * https://www.youtube.com/watch?v=XCrAPcUzOdw https://www.youtube.com/watch?v=XCrAPcUzOdw So if an intersection is (e.g.) four-way, and one particular entrance monopolizes things than it can be given red at times and the others green (and than one-green/three-reds). See (e.g.) "Performance and Safety of Roundabouts with Traffic Signals" by Tracz and Chodura: > The paper presents designs, advantages and some drawbacks of various layouts of roundabouts with traffic signals, used in urban arterials on crossings with large traffic volumes. The authors analyze signal settings with alternative phasing used at intersections that can provide the intersection capacity of about 6500 veh/h in 2x2 lanes arterials or even 8000 veh/h in 2x3 lanes arterials. Accident statistics for roundabouts with traffic signals in Krakow are also given and discussed. In addition, presented are practical examples of changes of signalized roundabouts geometry; reconstruction into a form of turbo- roundabout and its effects regarding traffic safety and good performance. * https://pdf.sciencedirectassets.com/277811/1-s2.0-S1877042812X00247/1-s2.0-S187704281204390X/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEDwaCXVzLWVhc3QtMSJGMEQCIE5WnkghO3ym2nZRbP0OiLhErx7SZMjhN2tGQ7fJv1%2BlAiA%2FEVEi10pDddQmTyzb5BsNSF5kJZeLUI%2BG6J9BruWwQSqyBQhlEAUaDDA1OTAwMzU0Njg2NSIMqGTQKVNtZjngJrwSKo8FQLAk%2FtcRFu0H5G2NZ8v4aYVe%2FAqFQj7hS7sZAlb7vqq84U%2FaJTlLto2VYGFrvgSQ5sgUBpCW4doiqejjJzlHdgXlUSZhdHCqT3laELbuamgjHZK8yCWnThDhUxz885rxJb%2Fu4oxU9K4kGHqLtFHVQ5Ff29STia0R2BncttigbbsFHN2eJgCp7bqcuAHTV6ik5zG88m6RelL1ILu%2FRUIb%2FuJSUDxHtIE9Ln9gR3YWiHApZkzJnTfbIv5rDKih0UL6PiI07YsX%2BSGjdmbilECV5XQeLLiqpHXWQFsfhlqcBE6RD6BabVhRw42R9k3CAkuJ%2BYTqOWu%2Bl11j%2BT%2FDam2RALWb48bQDZlmN1uOUXyc5bLVwzP0sf4vFjVDzmWgs3Ap8SHwDifCCu0i8NfDoU91HVkJSdihb8XSN4mdV0lEdB0h1LrDKRa60VU90kC3ZUx1TNl00TDfoynBdaBdrOcRJYSWj01Ioecu8daIoF31n1zxjKkLD7H3OZtkll0q%2FbdJu2yionKn0KDa2UcM8t%2BCckacz9F2BF1EZXMH0DwBDvtt%2BwYaUyREuG5899Wa9IFhw6yAdzFq%2FcOA2LB8U15%2FrO9jjJC2lbsK4OrLTqCkWh23UJ3KwvOTjvNIbeejodrGt0tjHq0rRHKb%2FCsMdJDE%2BN1WFacGZxYwc01vxobdOas5aE0HKDAZxpYdRSK3naMAxfNJwTENYA9IHLOdmTJosaYTt15I5CWLWfzuhV9jG%2BnLyoWe9T%2FkRAQYywK18C9S0MJ9tDGz6pfV7HD2BDSb%2BxD5y7UVCZmptypQXb2QDaiMBTtCOq2JsInDObHRnifQ7%2BlCjbZAJpz4wQU44Ef5eggm2Mam9UoiCXJU8OOEVjCS5OWpBjqyAeHpnPdjraHUzg80EWT8lKyBIdwnAzPz3A2uAPF6FEhft5i%2Bi%2B7M0f9e37nJ30SR5gXjljYMNUQptYRRxoKhP%2F8UmNJUUCzwQ6Px%2F4e5WzZDnbAvN72JlH1CLUKTO7U%2Fgxi3OsNZUZ4QPBzet9rTHQyN%2Fr2wNBnEJoiUyKTYkF697%2FAHoyaI9bTTabw9NRSfB4AL2ONezr2tIu5jF0ZaziLY1%2B04BckG3n%2BgBRph%2B1Nm2vw%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20231025T203857Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTY6RVOT4WD%2F20231025%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=6221ad8d5af1785a45e1d39e00bef345de017380fc95fa3e0086e62177ae870d&hash=18bd6a8629a15ca415690d47786abf64c2e357d86dffc9e0df5f2697cedbd635&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S187704281204390X&tid=spdf-c05f0068-701e-4a37-a7a6-aea8542e82f6&sid=1a03793351ba33443788f464e78bba693df9gxrqa&type=client&tsoh=d3d3LnNjaWVuY2VkaXJlY3QuY29t&ua=19015856020a5a56545e&rr=81bd442079863a00&cc=ca https://pdf.sciencedirectassets.com/277811/1-s2.0-S187704281... And §8.1 Traffic Signals at Roundabouts: * https://www.fhwa.dot.gov/publications/research/safety/00067/000678.pdf https://www.fhwa.dot.gov/publications/research/safety/00067/... Also: * https://www.access-board.gov/research/prow/literature-roundabout-signalization/signalization-of-roundabouts/ https://www.access-board.gov/research/prow/literature-rounda...
• kridsdale3 3y ago
  Learning to handle a 3-lane wide roundabout outside Inverness Scotland, in right-hand-drive (that I only had 2 days of experience with) in full rush-hour was pretty fun.
• devnull3 3y ago
  Simple roundabouts are definitely good but in UK I have found spiral roundabouts error prone if you have not driven on it before Example: [1] When visiting for the first time on a specific spiral roundabout: 1. Lane markings are faded 2. You do not know the specific lane unless you come very close to it and have to make a quick decision 3. Often due to queued traffic you cannot even see the lane marking until its too late. Because of this I have seen people change lanes on a roundabout because they made a mistake and its dangerous. [1] https://www.google.com/maps/place/Sainsbury's/@51.5080462,-0.5816409,173m/data=!3m2!1e3!5s0x48767ab1f69dfbc7:0x480bc3e7f0621fd4!4m6!3m5!1s0x487664d7ccdb3e33:0xdc0fd0ed013eb0d1!8m2!3d51.5080945!4d-0.579077!16s%2Fg%2F1ptvv67nn?entry=ttu https://www.google.com/maps/place/Sainsbury's/@51.5080462,-0...
  • ikekkdcjkfke 3y ago
    If youre going more than half way around you want to go on the inner
  • throw0101a 3y ago
    "Spiral Roundabouts | Understanding what to do": * https://www.youtube.com/watch?v=e6TsX9Ob91w https://www.youtube.com/watch?v=e6TsX9Ob91w I'm more curious about the straight-through path of [1] above.
    • devnull3 3y ago
      There is a sign board which tells whether to take the middle road or left [1] This is the round-about layout [2] None of the above tell the precise lane to take. Only when you enter the roundabout you will know. See.[3]. Imagine cars waiting on these markings. This is what frustrates me the most. [1] https://www.google.com/maps/@51.5066257,-0.5789164,3a,75y,326.22h,95.34t/data=!3m6!1e1!3m4!1sITsslQOLf6wfrkVJAGWzvA!2e0!7i16384!8i8192?entry=ttu https://www.google.com/maps/@51.5066257,-0.5789164,3a,75y,32... [2] https://www.google.com/maps/@51.506316,-0.5784722,3a,37.5y,294.41h,93.18t/data=!3m6!1e1!3m4!1s3g-q9_qQvfAXgaCI7q8YeA!2e0!7i16384!8i8192?entry=ttu https://www.google.com/maps/@51.506316,-0.5784722,3a,37.5y,2... [3] https://www.google.com/maps/@51.5076664,-0.5804344,3a,75y,296.87h,79.1t/data=!3m6!1e1!3m4!1sLYadgZBR4tZKY1tp7KZtBQ!2e0!7i16384!8i8192?entry=ttu https://www.google.com/maps/@51.5076664,-0.5804344,3a,75y,29...
• tunesmith 3y ago
  Two-lane roundabouts still confuse me a bit. Even the video tutorial in that article has what looks like a problem to me. At 1:06, the pink car in the right lane skips the first exit. How does the orange car in the left lane know it's safe to take the second exit? That's a collision risk right there if the pink car wants to continue counter-clockwise.
  • attheicearcade 3y ago
    The pink car is in the wrong lane if it wants to stay on the roundabout for a later exit. The pink car can take either the first or second exits here. The orange can take the second, third, etc.
    • margalabargala 3y ago
      The lines on the road are incorrect in the video; the pink car should not have been able to go straight. Based on the lines used in the 2-lane roundabout in the video in question, all right lane entrances should be forced to take the first exit. Properly signed roundabouts make this clear. Here's an example: https://www.google.com/maps/@44.1104851,-121.2794584,97m/data=!3m1!1e3?entry=ttu https://www.google.com/maps/@44.1104851,-121.2794584,97m/dat...
  • Gare 3y ago
    It is now considered that multi-lane roundabouts (which permit lane changing in the roundabout) are a bad idea because they have too many collision points. Turbo-roundabout is a much better alternative: https://en.wikipedia.org/wiki/Roundabout#Turbo_roundabouts https://en.wikipedia.org/wiki/Roundabout#Turbo_roundabouts
  • JohnFen 3y ago
    Multilane roundabouts in my part of the US are absolutely terrifying because people don't know how to use them. Accidents and close calls are amazingly common. As a result, I drive out of my way to ensure that I avoid them. Simple roundabouts are fine.
    • 3y ago
• halfmatthalfcat 3y ago
  Long time Carmel, IN resident here, AMA. Yes, almost every intersection has a roundabout for a population around 100k. Yes, they are efficient. Yes, it’s a pain using them when people who don’t know how to use them, use them.
  • ToucanLoucan 3y ago
    Checking in from WI here. We started getting a lot of them in the greater Green Bay area about a decade ago. It's better-ish lately, but there are still consistently issues with drivers who don't understand how they work, and there are frankly too many of them located around light-industrial areas. I have no idea how these get approved for those locations: for commuter cars, they're excellent. For LTL trucks, they are highly problematic, cause traffic backups, and due to the nature of those large vehicles, basically the only way they can proceed through them is to wait until there is no traffic at all in any direction, or simply pull forward and hope the driver in the roundabout can/will stop in time to avoid an accident. It's also worth noting: this are notably more difficult to traverse during fresh snows. While starting and stopping is certainly an issue in snowy intersections, a roundabout introduces a lot of turning, and especially so in cases of spiral ones. Two-lane roundabouts basically have to become one lane during a heavy snow, there just isn't enough grip to safely maneuver one with multiple lanes. And that's with Wisconsin lanes, which are notably large among US states.
  • city41 3y ago
    > Yes, it’s a pain using them when people who don’t know how to use them, use them. Here in Michigan there are roundabouts everywhere. And I'd estimate oh maybe 20% of the drivers know how to use them. Because of that, I absolutely hate them. A roundabout around here is just a total luck of the draw on what you will get: people treating it like a four way stop, people ignoring it completely and just blasting straight through at top speed, people going into the roundabout then stopping at every merge point, people going into the roundabout and stopping to let someone else merge in front of them, on and on. I'm still amazed at what people do. I suspect the people who blast through it at top speed and cause an accident cause other people to turn into the type that treat roundabouts with extreme caution. Just outside my neighborhood I must have seen 10 accidents in the past two years alone. That's a lot of accidents at an otherwise low traffic intersection.
• nemo44x 3y ago
  I love roundabouts. Driving in the UK is a revelation. You just sort of keep going and driving is a bit more fun. The drivers are also better than in the USA. Which is why I think there’s often resistance here. Every time a roundabout is proposed near me there’s a vocal group of opposers. I just don’t really get it since in many cases a roundabout is preferred to an intersection in my opinion. But one comment I read summarizes it I guess: “Drivers here are just too dumb for a roundabout. We can trust them to think.” And I guess I sort of agreed. Driving in America is weird because so many people do things like passing on the right, not using turn signals, and driving the wrong speed in whatever lane they’re in causing chaos.
• solardev 3y ago
  The just-released Cities: Skylines 2 video game also features roundabouts! They're a huge part of the transportation networks now: https://www.pcgamesn.com/cities-skylines-2/roundabouts https://www.pcgamesn.com/cities-skylines-2/roundabouts Mini Motorways also had them from the get-go, and they're much more robust than simple 3/4/5/6-way intersections.
• dfee 3y ago
  Just adding to the already rich discussion an anecdote about stop signs preceeding a round-about: worst of both worlds. Example: https://www.reddit.com/r/bayarea/comments/10pihgk/roundabouts_with_stop_signs_why_is_this_a_thing/ https://www.reddit.com/r/bayarea/comments/10pihgk/roundabout...
  • js2 3y ago
    Richmond has a circle with a traffic light for exiting! If you stop for the light when it's red everyone honks at you. https://maps.app.goo.gl/BVrKXUqV6Ck7QTdQ6?g_st=ic https://maps.app.goo.gl/BVrKXUqV6Ck7QTdQ6?g_st=ic The problem is that it's not really a circle. It's like half-circle/half four-way stop.
• hasbot 3y ago
  What confuses me on roundabouts is the intended speed. Some are very tight and requires slowing down to 15mph and others can handle faster speeds. Rarely is the intended speed marked. A new roundabout in Brevard, NC has a very tight turning radius. There is a sign warning drivers in the outer lane to watch out for tractor trailers who will have to take both lanes to navigate the circle.
  • oldbbsnickname 3y ago
    Yes, some residential ones are absurd. This one would've been better as a 4-way stop because there's no way to see traffic from all other sides due to the angles and obstructions. https://maps.app.goo.gl/GWoqaxNfVanXLymp6 https://maps.app.goo.gl/GWoqaxNfVanXLymp6 One went in here where people normally drive 60 mph: https://maps.app.goo.gl/Ugnm36mkeHs2zpu7A https://maps.app.goo.gl/Ugnm36mkeHs2zpu7A On Clark straight through, I would look for approaching traffic from either side or ahead and would cut across the hatched area, mostly maintaining speed. It's honestly better than stop signs or stop lights.
    • crote 3y ago
      The first one is totally fine. When you're entering the traffic you're driving at about 15-20mph due to the sharp curve forcing you to, so there is plenty of time to look for traffic already on the roundabout coming from your left. With the exception of the signage, I'd say this is a textbook example of a roundabout done well. The second one is a bit of a mess. The fact that it is physically possible to take them at 60mph means they screwed up the design. They should've used something like slightly raised cobblestone for the hatched area, and they should've used a raised shoulder at the entrance/exit. This roundabout looks like it was designed by someone who has only ever seen it in a textbook, and never actually driven on one.
• oldbbsnickname 3y ago
  Roundabouts for high traffic areas are good. The problem is when they are overused in low traffic areas where they create obstacles to efficient continuous motion, increase pollution, and waste time. PS: One place that doesn't do proper traffic design (or architecture): Texas. They insist on placing massive concrete dividers everywhere and have camouflaged by wear obstacles in the middle of paths that are injurious to bicyclists. It's nothing like the Netherlands where there aren't many random, dangerous surprises.
  • DeRock 3y ago
    > The problem is when they are overused in low traffic areas where they create obstacles to efficient continuous motion, increase pollution, and waste time. The alternative (at least from my experience in the US) is a 4-way stop, and is worse for all those criteria.
• Zanni 3y ago
  Here's an explainer on "conflict points" [1] which seems central to the argument. Most folks intuitions are correct that roundabouts eliminate cross-traffic (major conflicts), but they also reduce merge, diverge and weave conflicts (minor). [1] https://www.apsed.in/post/conflict-points-at-intersection https://www.apsed.in/post/conflict-points-at-intersection
• michaelteter 3y ago
  Two lane roundabouts are pretty good. More than two lanes are very questionable. And roundabouts which include... stoplights!?!? are just stupid. I live in the Netherlands, where roundabouts are very common. In many cases, they are an improvement. But NL is also a huge bike country. And at most roundabouts, bikes have right of way. So as a car driver, you have to worry about other cars as well as bikes which may turn (go away from the roundabout) or continue (cross the adjacent road circularly around the roundabout. In good visibility conditions, it's ok. And by OK, I mean it can still really f* up car traffic, especially when it is a high traffic area not far from a school. In lower vis conditions, and/or when electric higher speed bikes are concerned, it becomes a whole new kind of danger. I would argue that the benefits of roundabouts diminish or fully disappear when the number of lanes exceeds 2, or when traffic lights are added to roundabouts, or (and!) especially when bike paths intersect with and circulate around the roundabouts.
  • LRVNHQ 3y ago
    > But NL is also a huge bike country. And at most roundabouts, bikes have right of way. The fact that it's on a case-by-case basis an not actually a consistent traffic law is really awful. To add insult to injury, the only signage is usually a yield sign painted on the road that is invisible as soon as it's dark and the road is wet. And this is of course further combined with the absolute scandalous amount of cyclists who don't have lights at night and are dressed in fully dark clothes. Roundabouts are already a traffic situation that require heightened attention as a driver, so in the interest of safety I believe crossing cyclists should yield to cars at the exit. It's too many things to worry about otherwise. But at the very least, make it the same everywhere so it's always absolutely clear to both drivers and cyclists who has the priority.
    • ryukafalz 3y ago
      > To add insult to injury, the only signage is usually a yield sign painted on the road Doesn't the red asphalt denoting a cycleway also typically continue across the exits when cyclists have priority?
• fnordpiglet 3y ago
  Seattle roundabouts are absurd - they’re actually not roundabouts despite being shaped like them, but are traffic slow down artifacts. But people insist on treating them like roundabouts despite being too tight a radius for some cars and the city advising to not treat them as such.
  • Clamchop 3y ago
    Traffic calming features: https://en.m.wikipedia.org/wiki/Traffic_calming https://en.m.wikipedia.org/wiki/Traffic_calming
    • InSteady 3y ago
      We have lots of these little roundabouts in Portland (not to mention all manner of other traffic calming features), and they are generally well placed. Almost exclusively used in areas with heavy bike and pedestrian traffic, where cars would otherwise be incentivized to speed and bypass heavy traffic on nearby arterials and busy commute routes.
      • fnordpiglet 3y ago
        Yeah I’m down with traffic calming measures. The issue is people treat them as actual roundabouts and instead of turning left say they drive around the circle. And they’re so convinced they’re right they will actually road rage if you properly turn at the circle without going around. Many vehicles are incapable of making the roundabout properly and run up on the curbs etc damaging the cars and the curbs and endanger people waiting at the corner to cross. The feature itself is fine by me, but the issue is it confuses people because it’s too similar to a roundabout.
• citizenkeen 3y ago
  Portland, Oregon has a roundabout with four stop signs and I've been mad about it for thirty years. Why?!
  • InSteady 3y ago
    Because its on a busy intersection and people are idiots. I've used it hundreds if not thousands of times on my bike, not to mention as a pedestrian. I would not do either one if not for the stop signs. I've seen so many idiotic interactions over the years that were only mitigated by the slow speeds starting from a full stop. People like to zoom down Cesar Chavez especially at night when traffic is light. It would be a death zone for pedestrians and cyclists under normal traffic circle conditions imo. Also, there are heavily used crossings for two different elementary schools within a few hundred feet of this traffic circle. The impediment to flow of traffic is probably intentional for that reason alone.
    • nonethewiser 3y ago
      But why not just put a yield sign? I can honestly see why absolutely no sign suggest you have the right of way.
• gumby 3y ago
  Inexplicably, the ones in the Bay Area are often installed with stop signs, which makes the point of a roundabout rather mysterious.
  • kazinator 3y ago
    Removing the middle area of the intersection has a safety benefit over the stop signs. Some drivers habitually ignore stop signs. Since it is a physical barrier, those drivers won't ignore the removed middle of the intersection, unless they are drunk, and in that situation it's unlikely two will do that at the same time, where we would have a fatality.
  • bertil 3y ago
    You are meant to give priority to the vehicles in the roundabouts. A stop sign forces a two-second pause over yielding. I’m not sure that’s a big hindrance, and given how drivers barely mark stops and ignore yield signs, that might be the only way to get drivers to actually look if it’s free before they go on the roundabout. The point is always to avoid frontal shocks by limiting intersecting paths and having instead merging lanes. Even with stop signs, those roundabouts do that.
• rcpt 3y ago
  Ctrl+f "pedestrian" Only one result and it's not even about roundabouts. This is how American traffic engineering is done.
  • davidw 3y ago
    It seems that a lot of American traffic engineering is about increasing automobile throughput at the expense of all other factors. Safety, expense, even how economically productive the street is in terms of supporting businesses and housing.
    • pnw 3y ago
      I would argue in locations like Seattle the exact opposite now applies. Lots of “road diets”, bike lanes and other engineering that reduces automobile throughput.
      • davidw 3y ago
        It's good to see some places trying to course correct after 70 some years of pretty much exclusive focus on automobiles. They have a lot of work to do.
  • lobochrome 3y ago
    Is your argument that roundabouts are bad for pedestrians? If so why?
    • adgjlsfhk1 3y ago
      The lack of lights and increase in number of crossings (for non-tiny ones) make them pretty terrible to cross as a pedestrian.
      • kdmccormick 3y ago
        (Warning: Anecdata) There was a multi-lane roundabout near me with traffic signals and pedestrian crossing signals and all. It was an absolute nightmare to drive through, bike through, or cross on foot. Cars pressured one another to drive aggressively, pedestrians had to wait for walk signals, cars got confused and blew through the crosswalks by accident even when pedestrians had walk signals, bikes were an afterthought... it sucked. They recently simplified it down to a single car lane and a single bike lane with priority (unsignaled) crosswalks at every entrance. It's slightly slower to drive through, but much less stressful. It's a joy to bike through. As a pedestrian, I love it because I don't have to wait for a walk signal... I just cross, and entering traffic is obligated to yield to me. So, in my head: single-lane roundabout > intersection > multi-lane roundabout
• Daz1 3y ago
  Half the videos on Dash Cam Australia are roundabout accidents.
• WirelessGigabit 3y ago
  Couple of things that go wrong with roundabouts: 2 lane roundabouts where the inner lane needs to give priority to then outer lane. The Netherlands does it a lot better with lanes that 'tear off', and you migrate naturally to the outside line. Roundabouts on roads with lots of North/South traffic can cause people who come from East/West to have to wait forever as they can't just jump on the roundabout. As long as traffic is coming and can enter the roundabout they don't have to allow anybody else on it.
• annica 3y ago
  I could see how these have benefits in some cases. There are also drawbacks… the uncertainty of who is yielding (except maybe by AI). What about snow and ice? If you do some searching there are plenty of reasons why you might not want roundabouts.
  • 2muchcoffeeman 3y ago
    > the uncertainty of who is yielding Same we know red light means stop. You make up a rule. In Australia anyone from the right has right of way.
    • annica 3y ago
      It’s not the same though. Red means stop. It is ambiguous as to who must yield precisely because there is no red light to indicate it. What would the rule be? Your best guess as to the speed and distance of the other driver?
      • worthless-trash 3y ago
        There is no ambiguity in practice because these only happen on T intersections. These rules also apply on low / moderate traffic + intersections with no issues mainly because you are expected to pay attention to the road and not just breeze through every intersection like a maniac.
        • annica 3y ago
          There is ambiguity in practice. Accidents do happen in roundabouts and t intersections without anyone driving like “a maniac”. The point is that the article doesn’t really discuss the drawbacks of roundabouts of which there are many.
          • worthless-trash 3y ago
            I was referring to the "give way to the right" theory, not the roundabout theory. Which you also must give way to your right. If humans are involved, of course there are problems, because humans are error prone, the question is if its a problem, which from my limited experience of 30 years of driving is not a significant problem in Australia.
• davidw 3y ago
  When my wife and I moved to Bend, Oregon from Italy, I was really shocked to see how much the city had embraced roundabouts. I hadn't expected to see any in the US, let alone more than 20 of them throughout the city. Not quite sure what the exact history was, but they realized a few years back that they cost less and work pretty well.
  • Moru 3y ago
    Spoke to a taxi driver here in town, he was pretty tired of them. Our small town has 70+, he had counted them... But they do make trafic smoother if placed right. Here however they use them instead of the normal highway crossings with elevated or lowered access roads. As you say, they cost much less and lowers the accidents a lot. But they are not fuel efficient on 80 km/h roads where you have to stop every 500 m because of another roundabout.
• jongjong 3y ago
  This article makes it sound like traffic lights are more common than roundabouts in the US. In Australia, in most small to mid-sized towns I've been to, roundabouts seem to be much more common than traffic lights. Traffic lights are mostly used in densely populated areas (e.g. town/city centers) because roundabouts take up more space.
  • maccard 3y ago
    Traffic lights are absolutely more common than roundabouts in the US. Roundabouts are rare, and often come with a 4 way stop in the same place
  • Dalewyn 3y ago
    >This article makes it sound like traffic lights are more common than roundabouts in the US. That's because they are. And speaking as an American driver: I prefer traffic lights. They require no thinking beyond being remotely aware of your surroundings, you can see where you want to go, and there's no thinking involved other than making your way across the intersection when it's your turn. Roundabouts involve far more mental load that I do not care for: I need to gauge if and when I can merge, because there's no traffic light controlling ingress and egress. I need to keep track of the exit I want that I usually can't see until the last moment. I waste my time going around again if I confuse my exit, which can't happen with traffic light intersections. TL;DR: Traffic lights are simpler, easier, and ultimately faster as far as I'm concerned. If the safety of crossing pedestrians is the concern, then I have a simple solution: A bridge over the intersection connecting all four pedestrian corners. Somewhat common sight in Japanese cities.
• microvark 3y ago
  The authors have never driven in Boston. I grew up and learned to drive there. It is literally the scariest traffic feature of Boston. If you go in a roundabout (or rotary as we call them), you need a will prepared (and it's a good idea to have hugged as many relatives as possible beforehand).
• VagabundoP 3y ago
  Roundabouts work well in my country, mostly, even the three lane ones. However a few weeks ago my wife encountered someone who obviously had a moral objection to the "round" in roundabout and drove in the straight line across three lanes of the traffic to the exit.
• annica 3y ago
  Hey kids. Big Ben. Parliament. https://youtu.be/iAgX6qlJEMc?feature=shared https://youtu.be/iAgX6qlJEMc?feature=shared
• saltharp 3y ago
  I’m an Australian who has spent a number of years living in the US, and to be honest I’m not sure roundabouts are that great anymore. Roundabouts might be more efficient for pushing cars through an intersection, but they’re less pedestrian-friendly. Yes that’s right, in this specific case, American cities are more pedestrian friendly than Australian and European cities. At best, a pedestrian has to take an awkward circular detour with a roundabout, and most Australian roundabouts DON’T have a zebra crossing like the picture in the article - so unlike a four way stop, pedestrians don’t have the right of way. If they did, it would likely destroy a lot of the (car-only) efficiency gains in busy areas. The other benefit of the four way stop is that every American just knows what to do when the traffic lights fail, since the rules fall back to the four way stop rules. In Australia, this can be a very dangerous situation until the cops arrive to direct traffic. (For the Australians who don’t know how to navigate a four way stop: you arrive at an intersection where all four entrances have a stop sign, so you stop, and then go through in the order that you arrived)
  • bogantech 3y ago
    > most Australian roundabouts DON’T have a zebra crossing like the picture in the article This is a planning issue not a roundabout issue
  • ChoHag 3y ago
    [dead]
  • vladvasiliu 3y ago
    > If they did, it would likely destroy a lot of the (car-only) efficiency gains in busy areas. Have you been to Paris? Not only do pedestrians here have to take detours, but it's a royal PITA for the car traffic, too! Who says you can't have it all? There seemingly are roundabouts all over the place. But, on closer inspection, those actually aren't roundabouts, but "circular intersections". Cars inside in the circle must yield to those coming in. Combine this brain-dead rule with the fact that nobody honors the "don't block the intersection" rule, and you get gridlocks all over the place even with light traffic.
• switch007 3y ago
  Roundabouts also don’t work so well in our ever more narcissistic society due to: - lack of indicating of taking an exit which which impedes the flow of traffic of the vehicles who thought they had to stop to give way - blocking entrance to the roundabout when someone’s exit has traffic - in heavy traffic, aggressively maintaining the normal give way rules instead of doing 1 for 1 for a fairer movement of vehicles Not that I’m arguing /for/ 4 way stops. I just think roundabouts work pretty well when you abide by the rules and apply some courtesy and respect.
• rapnie 3y ago
  In the Netherlands we had a huge phase of replacing regular crossings with roundabouts, which I consider to be an improvement. Now, however this is followed by a re-engineering phase of many of these roundabouts. The 2-lane ones, where a driver needs to pre-select whether they want to go a quarter round (turn right in Netherlands) or select for straight-ahead and 3 quarters round. The lanes on these roundabouts are separated by a rather high ridge to avoid drivers changing their mind and change lanes. This probably done for safety, except that they feel more unsafe now, by introducing "choice stress" upon entry of the roundabout, especially if the road directions aren't very clear. To me it feels like over-engineering.
  • meheleventyone 3y ago
    All the different rules for roundabout are fun. In the UK you’re expected to filter to the outside leave. In Iceland the person on the inside has priority to leave so you can still enter the roundabout but need to watch for someone already on the inside wanting to leave at your first exit. The rules are similar to the Netherlands in that you either go straight or 3rd exit from the inside and should only go first exit on the outside, although it’s totally possible to carefully go all the way on the outside. I still find the Icelandic system mildly bonkers but not due to the choice stress as it’s usually obvious which lane you need.
    • rapnie 3y ago
      Yes. One gets used to the system and then it works okay. That ridge dividing lanes may be there for safety reasons.. but one thing I observed is the anxiety to choose wrongly, and the subsequent road rage when wrong decision was made. Both intoducing to my noob eyes new safety hazards. And then I didn't mention cars that deliberately drive over the ridge.
    • xnorswap 3y ago
      Careful with terminology too, because "inside" and "outside" don't mean the same thing to different drivers, particularly in the UK compared to elsewhere. Many people hear "inside lane" on a motorway and think it's the "fast lane" near the central divider but that's actually the "outside lane". ( source: https://dictionary.cambridge.org/dictionary/english/outside-lane https://dictionary.cambridge.org/dictionary/english/outside-... ). But that terminology has been confused over time and so many people get it the wrong way around that the DVLA has stopped using it in the highway code.
• alex-moon 3y ago
  Amazing to see a "What is a roundabout?" article living in UK. The way they are put in over here you get the idea traffic engineers not only love them, they are in love with them. I largely detest them, if I'm very honest. They can be done really well, but most aren't.
  • switch007 3y ago
    Ditto! I once had a daily commute that involved 22 roundabouts each way. One every 2.5 miles on average. The smaller ones with infrequent and low traffic cause a slowdown for everyone unnecessarily - that’s a lot of break dust and fuel to accelerate again But I’m no traffic engineer so what do I know!
• penguin_booze 3y ago
  The _main_ rules are rather simple: - Slow the fuck down - Slow the fuck down - Expect--and tolerate--others to make mistakes
• buro9 3y ago
  Swindon, UK would like to remind the World that recursive roundabouts are a thing too. https://i.imgur.com/4pMhdMl.gif https://i.imgur.com/4pMhdMl.gif
  • hnbad 3y ago
    The video embedded near the end of the article also shows this particular roundabout.
  • pbmonster 3y ago
    How is that a thing? Why not just have a two-lane roundabout with the third lane skipping the roundabout and going to the next exit directly?
    • mrtksn 3y ago
      According to this video[0], it reduces the fight for space. IIUC, the idea is that this structure allows the flow to avoid the pile ups because you have more than one way to do something and if the one way is too busy you can take the other. Imagine a single roundabout with large number of lanes that can go just one way or exit the roundabout, then you can easily have a pile up in one exit block the drivers haded to the other exists. However, if the roundabout can go both directions the drivers can go through the other side of the centre. [0] https://www.youtube.com/watch?v=6OGvj7GZSIo https://www.youtube.com/watch?v=6OGvj7GZSIo
      • mcv 3y ago
        I don't know, those images of cars standing still on the roundabout are not very convincing that this is an efficient way to do it. I'd love to see this compared to the more structured Dutch turbo-roundabouts: before you enter the roundabout, you pick the lane for your exit, and you just follow that. You only cross other traffic once, on entering the roundabout. After that, it's smooth sailing to your exit.
    • baz00 3y ago
      We have another one which is just as cool. https://imgur.com/WfFXmBg https://imgur.com/WfFXmBg https://imgur.com/IFIZI2q https://imgur.com/IFIZI2q They actually work really well. I'd love to see some of the things that generative ML could do in this space :)
• hellotheretoday 3y ago
  I grew up in a touristy part of New Jersey near the beach and roundabouts were interesting. In the off season they were a fine and normal part of driving that the local population were generally used to. Occasionally you’d have a new driver or out of town person that would be confused but that was somewhat rare. Then the summer months would come and the circles would be a nightmare, filled with dipshits from the surrounding states that had no idea of how they worked despite the fact that the majority of them were single lane! You would really dread the double lane ones though as they would be filled with people who would have no idea how to proceed. You would often see people go around several times before they’d finally exit when there was a lull in traffic
• Rapzid 3y ago
  Roundabouts turn into absolute shit shows when backed up. The end.
  • crote 3y ago
    Luckily most roads are rarely if ever backed up, and the increased throughput of roundabouts compared to traffic lights or stop signs makes this even less likely to happen. Roundabouts work pretty well for all but the busiest roads.
• bheadmaster 3y ago
  One thing I love about roundabouts is the efficiency of the algorithm, compared to the classic semaphore-controlled crossroads. Since the inbound cars are required to yield to cars that are already inside the roundabout, the cars inside the roundabout are always guaranteed to exit the roundabout in a reasonable amount of time (assuming the exit lanes are not blocked), which means that there will always be new empty spaces for inbound cars to enter in an opportunistic way. It feels kinda like Ethernet for traffic.
  • datavirtue 3y ago
    Adorable. Where I live people stop in the roundabout when they see other cars coming or they stop at the roundabout if they see any car approaching. People just don't get it.
    • bheadmaster 3y ago
      Well, I don't know where you live, but where I live, if you're entering the roundabout, and cause an accident by not yielding to the person who's already inside the roundabout, it's entirely your fault and you (or your insurance) pay the damages. So anyone who's inside the roundabout can be pretty sure that nobody will slide in in front of them.
      • datavirtue 3y ago
        And yet they keep stopping...don't know what to say
• TedHerman 3y ago
  Allow me to explain why at least one of them is so annoying. The roundabout is atop a hill; there is little visibility of what traffic is approaching from other directions because the hill is steep. Motorists don't bother signaling how far around they will go. I, riding a bicycle on a sidewalk, wish to go straight across the road. However I can't always see that someone is entering the circle. And even if I do see someone is entering, I don't know when they will exit. Compare this to an ordinary stop-signed intersection, where it is clear when vehicles are not turning and I can directly cross.
  • Garvi 3y ago
    I see your one roundabout with poor visibility and raise you two regular intersections with one fatal crash each year each. Both in the radius of one kilometer (of my current position). Checkmate atheists. Also my spellchecker is pointing out that kilometer is not a real word.
• moribvndvs 3y ago
  I like roundabouts but American drivers on average have no idea what to do with them, not even from a common sense perspective. To be fair, American drivers are vanishingly able to handle four way intersection, but I digress. There are two roundabouts near me. The same two problems are rampant. 1. Failure to yield and yoloing into the circle at or nearly at full speed. One of the circles has a full stop sign, where some drivers seem to think that just because they stopped they are entitled to go next and the traffic already in the circle should and will stop to let them go, like a four way. The other doesn’t have stop sign, and I think people take the lack of one to mean they don’t have to yield or in any way pay attention because, hey, no stop sign. Admittedly, part of this is due to shitty design of the circles themselves. 2. Cars in the circle suddenly exiting without signaling, often veering across the outer lane of traffic. Part of this is driver’s education issue (I don’t think they taught us about roundabouts when I got my license several decades ago), part is the fact that in general people are allergic to signaling and have no awareness of other vehicles around them, as we have the same problem on highways. Perhaps this is more of an awkward transitional period for their use in the States, but honestly I think the bigger problem is we on average have very poor roadmanship and inconsistent road design.
  • Fatnino 3y ago
    Stanford University has been installing roundabouts in recent years. But they put pedestrian cross walks across all the entrances and exits. So you find yourself driving around and come across a car fully stopped in the loop because some kid is crossing the exit on foot.
    • bonton89 3y ago
      We had a roundabout like that with stop lights in the middle for the crosswalks, although I think the crosswalks were later removed and rerouted foot traffic elsehwere. I felt like everyone was complaining people didn't know how to use it but it seemed obvious to me the designers didn't understand the concept either. The crosswalks seemed to exist so the center green could be used a part. I'm not sure how many people enjoy sitting in a part literally surrounded by exhaust fumes and road noise. The same roundabout has double lanes for only half of the circle so if you are not familiar with it you may find yourself forced to exit suddenly at a turn you didn't want because the lane stops existing. My understand was the point of a roundabout was that traffic always kept moving inside them and you shouldn't stress if you miss the turn because you can just go around the circle to try again.
• dp-hackernews 3y ago
  Roundabouts are SHIT - especially so when they eventually acquire traffic lights - leading up to them, and finally actually on them... In the UK its priority to the right, meaning if there's something coming around the roundabout, you must/should wait... Which only works of there is a gap in the flow of traffic big enough for you to jump into... Don't worry USA, you'll soon regret your decision to introduce roundabouts. Stick with your sensible "right on red" logic, and your sweeping circular on/off ramps (yeah, you and Canada have plenty of space to do those) - they are genius for maintaining traffic flow (not so convinced about the traffic lights leading onto the freeway though at rush hour times!) If you fancy a giggle of what mayhem roundabouts can cause, try searching for "spaghetti junction" near Birmingham England, or "the magic roundabout" of Swindon England fame - they are priceless! Enjoy! ;-)
• DrScientist 3y ago
  Big fan of roundabouts - generally they keep the traffic flowing much better than lights and work well for cars. However if I'm on a bicycle, or I'm a pedestrian trying to cross the road near them, they can be more dangerous. There is a special kind of roundabout that is designed to tackle this issue - the so called dutch roundabout ( at least in the UK :-) ) however it does require drivers to know how it works - so there is always a chicken and egg problem as you introduce them.
• P_I_Staker 3y ago
  Yet the most dangerous intersection in the county was the only one with roundabouts.