Safety benefits of roundabouts
theconversation.com
theconversation.com
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...
* https://www.youtube.com/watch?v=e6TsX9Ob91w
I'm more curious about the straight-through path of [1] above.
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,32...
[2] 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,29...
1. They switched from 3 lane traditional to 2 lane spiral roundabouts. There are signs well before you enter the roundabout telling you what lane you need to be in, so you can get into the right lane early. We have a lot of snow in winter, so road markings are not visible.
Example of a sign indicating which lane you need to be in. After this sign, there are two more signs indicating lanes before you get to the roundabout - the next has destination names.
https://maps.app.goo.gl/zJLaFC78i232mUkh6
2. The lanes on the roundabouts have solid white lines which you must not cross. You can only cross lanes to go more towards the center. I'm surprised, but people actually follow this rule.
Example of lanes (and a rare sight of police...)
https://maps.app.goo.gl/HbnkXYkacX3dfq4j6
3. They added speed bumps on the roundabout. This slows down the traffic on the roundabout, giving more chance for vehicles to enter.
Also, on the small side where you have traffic circles rather than roundabouts, those also suck.
There are "traffic circles" that aren't roundabouts but just a round block in the middle of an intersection that requires the traffic to move around in a circle so cross traffic is slowed. Also called a "traffic calming circle."
https://www.seattle.gov/transportation/projects-and-programs...
That could also be a location specific term too. These circles are very common in Seattle.
Look up on wikiprdia, there are even different types of roundabouts
[0] King Charles is so uncharismatic I do not acknowledge his existence
Interesting. Can you elaborate? We have a few of them (and growing) by me and they’re fantastic as far as I can tell. No stopping every block for stop signs, I’ve seen landscaping truck with trailers sneak through them fine, and it’s so much easier on a bike or while walking. What’s the downside?
People generally don't slow down for lights, and lots of times accelerate to make it through before it turns red.
A three lane roundabout may be annoying when encounter as a tourist but the majority of locals going about their daily commutes quickly master them. For a three lane roundabout the inner lane is left turn only. The inner lane is left turn or straight and the right lane is right turns only.
The ones in my area have ample signage indicating which lane allows for each type of turn.
I’m much more skeptical about how roundabout users fare when they are people walking or riding bicycles. At least in my city, we've had roundabouts for years, and the yield rate for pedestrians is ghastly— like, sub-50% of drivers stopping for someone waiting to cross and remaining fully stopped until the person is completely off the roadway. In theory this is a fine of hundreds of dollars ("failure to yield to crosswalk"), but it appears to receive basically zero enforcement in practice.
As a result, the fancy multi use paths that accompanied our roundabout installations get little use, since it's obvious to anyone who tries them how dangerous and unprotected they are.
Roundabouts feel safer than a 4 way intersecting when I'm in a car even if it's annoying to have to slow down and accelerate again when there is very little or no traffic, which is normal in the countryside. It also consumes more fuel, wears the car, adds to pollution.
It's different when I'm riding my bicycle. Roundabouts put me closer to cars, especially if there are traffic dividers that force cars closer to the side of the road. Then cars are usually slower than a bicycle in a small or medium sized roundabout (think of race bicycles with drop bars,) which adds up to chances of being packed between two cars. My feeling is that what's good for cars is bad for bicycles.
As a cyclist I can see what's around me much better than when I'm in my car. Intersections don't feel like a problem because of the extra visibility. When I'm riding I long for old times straight roads, with a line on the side and half a meter of asphalt on the other side to ride on. No roundabouts, no speed bumps especially the 3M style plastic ones, which I can jump but they are annoying. All those safety devices, including roundabouts, increase fatigue and danger. They are also the main reason for crashes in bicycle races but that's not an issue for normal people.
Finally, as I both drive and ride I know how to behave not to put in danger the cyclist. When I drive I don't overtake bicycles before a roundabout because they'll be at least as fast as me. I don't overtake when there is a short traffic divider which narrows the road. A long one, oh well, I have to. Same thing when I approach an intersection where I have to yield or stop. Bicycles will be definitely faster there because they can look around better than me and decide what to do quickly.
When I ride and I'm approaching a roundabout or entering a short narrowing of the road I look behind me and if it's safe I lean a little to the center of the road to prevent cars to overtake when they'll be forced to come close to me.
"Researchers in Belgium found that single lane roundabouts without a protected bike lane increased crashes by 93%, while Danish researchers said roundabouts that did have separated lanes saw an 84% reduction in crashes."
CNBC: Roundabouts Are Safer. So Why Does The U.S. Have So Few Of Them? https://www.youtube.com/watch?v=atORPw-w83I
"All those safety devices, including roundabouts, increase fatigue and danger."
They literally distract from the traffic when you aren't in a little isolated house on wheels where people are prone to forget that traffic even exists. All those things designed to help getting a driver's eyes off WhatsApp require cyclists to get their eyes away from traffic.
On the topic of roundabouts, one thing I rarely see discussed (never?) is that traffic lights conveniently compress the vehicle stream into packets of high and low intensity, greatly helping smaller intersections downstream. Roundabouts on the other hand flatten the vehicle frequency and of there's a difficult place to enter or cross the stream, even a modest amount of traffic can be too much. In the end everything that isn't a roundabout can only be navigated by relying on someone in the dominant stream showing off compassion with those waiting. This makes everything go even slower and you quickly end up with even dominant streams going less than walking speeds.
I have a hypothesis that roundabout-dominated road graphs are particularly prone to effective throughput dropping once a certain threshold of throughput demand is reached. Traffic light dominated graphs are immune to this if drivers are just a little careful to not enter an intersection before they can assume that they will be able to leave before the lights change.
You might have a curve leading up to the round about plus roundabout signs, plus give way signs, plus 300, 200, 100 yard markers, plus painted lines on the road that get closer together as you approach, and finally the <<<<< sign on the roundabout itself.
At least where I live, there are two rules for traffic circles: (1) yield to traffic that is already in the traffic circle, and (2) when two cars arrive at the same time, yield to traffic on your right.
Rule 1 is the same as for a roundabout, but rule (2) is a bit strange when the two are put together. It creates a scenario where if the leftmost car doesn't yield for whatever reason (perhaps they thought they arrived a microsecond earlier), then now they move forward and become "traffic in the traffic circle", which means they steal priority and the right-most car now has to yield to them. If the rule were flipped the other way, such that we default to always yielding to the car on the left, then this wouldn't happen; it would work just like a roundabout, and the order of yielding priority would be the same regardless of agreement on the exact timing of when each car arrived at the traffic circle.
So, why is it that at a traffic circle we yield to traffic on the right, rather than the left? Is it just to be consistent with 4-way stops?
Yeah, that seems mad.
Personally I find it confusing that yielding works the opposite way on roundabouts and 4-way stops, and nobody else in my neighborhood seems to know what to do either. Whether people yield to me seems to depend mostly on the size of the vehicle I am driving.
There are a few non-standard roundabouts that has no yield sign and the lane goes straight into the roundabout but then it usually doesn't have an outer lane before that entrance.
Roundabouts are fine if the rule is, "Just get in there without hitting anybody and go around until you're ready to leave," but expecting anything more than that from most drivers is a lost cause.
We have tons of 2-lane ones and everyone understands them…
e.g. for a standard two lane roundabout with four exits, if you enter in the left lane, you can exit directly out of the 2nd, 3rd, and 4th (i.e u-turn) exits, but always in the left lane of the exit. If you enter in the right lane, you can exit out of the 1st or 2nd exits, but always in the right lane of the exits. With this design cars travelling alongside you can never cross your path, only cars entering the roundabout ahead of you can cross your path and it's their responsibility to yield.
The thing that most often causes problems is people in the outer lane NOT exiting (e.g. thinking they can take the third exit from the right lane) and swiping the car in the inner lane correctly taking the second exit.
In practice, people are not able to navigate two-lane roundabouts in a compliant and safe manner. Any intersection of roads busy enough to have two lanes in each direction is too busy for a roundabout to be safe.
I think drivers will get used to them and in practice there will be few collisions.
I think drivers will avoid them at all costs since even low speed collisions can cause extremely expensive repairs (and even total an older vehicle) meaning they'll never get the practice they need to navigate them safely, yet eventually those drivers will find themselves in a situation where a roundabout can't be avoided and suddenly it's chaos for every car in the intersection.
Even if multi-lane roundabouts were suddenly everywhere we'd probably need generations of new drivers trained to use them in drivers ed classes as teens before you could just trust people to be able to navigate them correctly
Yes, in that case a driver not understanding the rules of the road (that you can't take the first exit from the inner lane, which is usually clearly signed) could cause an accident. The exact same way turning right from the left lane in a signalized intersection can cause an accident. The question is, what's the damage of an ignorant driver and how fast do people learn? The research indicates that right-of-way incursions in a roundabout result in dramatically fewer injuries than right-of-way incursions at other types of intersections, and the research also indicates that contrary to your belief, drivers actually do learn how to use them.
The exception is you can obviously not shoot straight from the left lane to the first exit.
In a 2 lane roundabout it is very simple. Enter in the left lane and you can exit 2nd or 3d, enter in the right lane and you can exit 1st or 2nd.
Where it gets complicated is roundabouts with 2 lane entry but only 1 lane in the third exit. Then you have to change lane right halfway through and be careful with people entering prematurely from your 1st exit, or people incorrectly staying in the right lane past the 2nd exit. It’s not always obvious but for those entering the rule is the same, since they enter after you, they should yield to you.
This however does not stop accidents to happen all the time in this situation because of drivers trying to get past the traffic jam by going inner lane in high speed and then exit in front of traffic trying to get to next exit. And mostly without blinking at all.
The US is unfortunately loth to install any sort of divider more than paint or a feeble plastic post, and less than a jersey barrier.
The 90->270 car sees the right indicator and lets the other car passed.
The real answer is somewhere between the above and the 90->270 car waiting to enter the roundabout because it is not sure if the other car is actually going 0->180 or 0->270 because they are a shit diver that doesn't indicate on roundabouts.
This is not true with most roundabouts in North America at least. If you look at the diagram GP posted, you do not change to the outer lane to exit. You exit directly from the inner lane. In fact, you NEVER change lanes in a roundabout. The reason this works (where the inside lane crosses the outside) is because the roundabout is small enough that the traffic in the outside lane has to let you exit as part of yielding to enter the roundabout in the first place. After that, as long as everyone respects which exits they're allowed to take from which lane, there is no more crossing traffic. In practice, if you are in an inside lane, you want to keep an eye on the outer lanes to make sure someone isn't trying to take a later exit than they are allowed.
From GP link:
> Do not change lanes in a roundabout
> Do not travel in the outside lane further than allowed as it may create a hazard for the vehicle exiting the roundabout from the inside lane
When you exit from the inner lane you necessarily have to change lanes because the inner lane is completely inside the outer lane. You may not think of it as a lane change because you're going across the lane not merging into it, but it is a lane change and you have to pay attention.
No, they have to yield to YOU because you're already in the roundabout. It's hard to believe, but trust me, this is just how it works and all of the links I've posted agree. The reason why it works is because when you're in the situation you describe, for the person entering at the second exit to be a factor, they would have to be entering as you're already alongside the second exit and in the process of exiting at the third. So they need to be yielding to you as they will be crossing your lane. Part of waiting for the gap is waiting for the exiting traffic to clear. Not for only YOUR lane to be empty.
Here's a video from Minnesota timestamped to them talking about exactly this scenario in detail. Namely, yielding to all lanes of cross traffic: https://youtu.be/CEhNboz5GPk?si=LxdVQZx0MHrYhl8w&t=196
> With multi-lane roundabouts, it is important to stop for vehicles in all lanes of traffic. Wait until there is a gap in all lanes of traffic and then enter slowly. Never try to enter alongside cross traffic or assume any driver's intended path. One of of the most common mistakes people make when entering a roundabout is failing to yield to all lanes of traffic. Yield doesn't mean just slow down or merge. Yield means that you must wait until all traffic in the roundabout has cleared before proceeding. Make sure that no one is in either lane of the roundabout and then proceed.
The video also has a good overhead view that is better than most at showing the scale of the roundabout. The important thing to note here is that to enter the roundabout, you have to cross the lanes that are exiting, not merge into them. So you are yielding to all exiting lanes.
The person following the outside route from 90 must yield before even entering. It's very confusing until you're actually in them, but they're small enough that what you're saying usually isn't really a problem (at least in well designed roundabouts). When the car at 90 enters the roundabout intending to take the 270 exit, they yield to traffic in ALL lanes that might be exiting. Not just traffic in the outer lane. If they were intending to take the 180 exit, they only need to worry about traffic in the outer lane (or people incorrectly changing lanes when exiting).
The shitty part about roundabouts is when people allow blocking of the view to the right on the round about so you are unable to see incoming traffic till its almost on the round about.
Newbie drivers I talk to/drive with are much more worried/unsure about crossings (both the ones without traffic lights and the big ones with many lanes) and of course about parking.
Of course, there will be SOME people who are clueless on roundabouts, similar to how there are always some people who will stop on a highway after missing an exit and pull back. But let's not argue about the long tails.
IMO if you learn to drive at a time when roundabouts are already ubiquitous, they are trivial. At least I found other aspects of driving more difficult.
What?? People do that??
My mind is blown. I've never once seen that happen, so the possibility never entered my mind. Now that I think about it, though, I should probably be more surprised that I haven't encountered it.
One that gets me every time I go past is one where there's like 20 signs saying that both lanes continue to the main road to the right (270 degrees around, the UK so driving on the left), but I don't think I've ever been through there and not have someone try to merge in to me trying to get into the left lane to exit, despite both lanes leading to that exit.
Of course the de facto standard here (which many people actually think is the law) would be "give way to the right" (i.e. left for US) meaning some people will proceed without stopping even if the car to their direct left got there just before them. I think this is predictable since more risk falls on the driver who is going to get T-boned in their driver side door if they don't stop so they will be naturally cautious.
I can't speak to the area you live, but where I'm from we get along just fine. Yes sometimes you still get the odd unfamiliar driver that doesn't understand them, but for locals there's a critical mass where roundabouts stop being avoidable and you adjust.
See also: https://www.iihs.org/news/detail/safety-at-two-lane-roundabo...
And that means everyone has to watch both left and right at the same time while also trying to figure out layout (Will the outer lane force me out when I do not what to? Some roundabouts are like that. Will the inner lane keep me trapped? etc)
It doesn't help that often those signs are pretty confusing all by themselves (at least the ones I've seen), and can't really be grokked from a brief glance driving by.
It would be better if all such roundabouts were consistent in how you should navigate them, but that isn't the case in my area.
Source? Not doubting you, just want something to reference in the future.
There seems to be quite a bit of literature that flatly disagrees with this statement. Perhaps you could add a source? The conventional wisdom where I'm from is that multilane roundabouts don't reduce the absolute number of crashes (and might even increase crash rates), but they still dramatically reduce the severity of crashes.
Canada:
> However recent data in the United States and Canada are showing that collision frequency at multi-lane roundabouts is often higher than expected, and sometimes higher than the prior signalized intersection. This trend is worrisome given that roundabouts are often constructed as a means of increasing safety. The good news is that fatal and injury crashes are almost always reduced with roundabouts, even if property-damage-only crashes are not.
https://www.tac-atc.ca/sites/default/files/conf_papers/weber...
Netherlands:
> Multi-lane roundabouts. These are less safe than single-lane roundabouts, but still safer than other types of intersection [22]. Multi-lane roundabouts are less safe because they have a larger number of conflict points, they are more complex, driving speed is higher, and they have a less sharp entry angle [23].
https://swov.nl/en/fact/roundabouts-how-safe-are-different-k...
US:
> Roundabouts force drivers to slow down and all but eliminate the most severe types of intersection crashes — right-angle, left-turn and head-on collisions. Single-lane roundabouts see fewer total crashes of any type.
https://www.iihs.org/news/detail/safety-at-two-lane-roundabo...
Two-lane roundabouts are larger; cars go around them faster. There is ambiguity. Some cars short-cut using the middle lane, and veer right out of it to their desired exit. Cars in the outer lane might be wrongly assumed to be turning off at the next exit. North American drivers get really confused by two-lane roundabouts.
I don't think these situations will typically lead to anything worse than fender benders.
The same intersection without a roundabout could be host to fatal collisions, when two vehicles enter at speed and hit each other in the middle.
Not at all. A large enough roundabout with good visibility from the approach can allow you to traverse it without slowing down at all - if the speed limits coming up to the yield line are appropriate, and traffic is flowing.
There's a sense in which a roundabout is just a short circular section of highway with a series of on and off-ramps around the edge. Well designed onramps allow you to merge without slowing, and off-ramps let you leave without disrupting traffic. Roundabouts can permit the same.
Since even a fender bender can cost many thousands of dollars in repairs that's still pretty terrible. Speed bumps slow drivers down too and don't risk people turning into you because they were trying to exit from the inside lane of a roundabout.
The two lanes are there in larger, busier roundabouts to reduce collisions, not for "slower traffic, keep right"; it's not a freeway. Cars enter the outer lane, and may use the inside lane to avoid other cars entering.
The problem is road users new to the road do not know which lane to be in already and they are pressured to go fast. The instant it looks like they've chosen a lane, a driver from behind who is familiar with the layout closes the gap in the other lane, trapping them.
This can be mitigated a bit by the first user having the confidence to slow down and straddle lanes until they are sure of the correct lane, but it's surprising how quickly such opportunities are missed.
The real problem is familiarity with lane layouts allows the road to operate at far higher capacity then normally possible and with less maintenance. They are squeezed to their limits in morning rush hours comprised of mostly familiar users. You'll even see users observing essentially invisible road markings because they're doing it from memory. No chance of you're unfamiliar with the road. Roads start to fail way before 100% capacity, but these lane markings allow that to be squeezed further during rush hours.
If you are in a wrong lane, the safest thing is to continue on it, exit the roundabout and comeback again or go around the roundabout.
Of course you could just not change lane, to the wrong way and safely correct your course later. This is preferable but people tend to get stressed out in those situations which is also bad for safety. Not to mention that a safe but ineffective road hasn't really achieved much.
I won't bother trying to expand on my comment to you, you're clearly not someone I'll be able to communicate comfortably with.
https://www.google.com/maps/@51.7874467,-1.278506,17.57z?ent...
Coming out of Oxford on the A4144 there are two lanes; the left lane is for taking the first two turns and the right lane for the remaining three. But, drivers unfamiliar with the layout who haven't seen the markings, or who fancy jumping the queue, will sometimes use the left hand lane to go straight ahead onto the A44. There's a similar situation coming from the A40 to the East.
I've seen a few accidents there and even been involved in one as a result of this (someone tried to undertake me at speed as I exited, and caused a collision, 100% their fault according to our insurers).
> drivers unfamiliar with the layout People familiar with the layout drive even when the markings are completely faded. It causes lot of anxiety if you are not familiar. It happened to me once where I was in a wrong lane. I continued on it as it was the most safest thing to do but the next exit was onto a motorway :). I was so angry with myself.
But of course not everyone notices every sign (and some drivers just wilfully disobey them if they think it'll save a few seconds...)
[1] https://www.google.com/maps/@51.787062,-1.2794264,3a,15y,317...
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.
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.
Doesn't the red asphalt denoting a cycleway also typically continue across the exits when cyclists have priority?
The confusion can arise inside built-up areas where there's a separate bicycle path, usually close to the car lanes.
I hate these so much. Seems to break the purpose of a roundabout in the first place - to let a single entry and exit pattern dictate the traffic.
Stoplights in them fundamentally break their benefit, which is smooth, one-way flow.
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.
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.
Bonus question: if you can, what happens if you drive a DeLorean at 88 miles/hour on it?
Every driver in the UK is used to sequences of two or three roundabouts, they are part of the driving test. As long as you are not bamboozled by the pseudo roundabout in the middle, you just navigate it based on principles you already know.
As other comments have noted, when drivers are less clear on the rules they tend to drive more slowly and cautiously - I think that makes double roundabouts "work out" most of the time.
Holders of foreign driving licences should probably be required to do a course, including these at least, before being allowed to use their licence here.
Apparently there are fewer accidents on the roads when the traffic lights aren’t working. The reason is exactly that - everyone is terrified and drives really slowly to make up for it.
We could accomplish the same with other forms of creative driver-hostile road construction and deliberately unproductive signage.
Only one result and it's not even about roundabouts.
This is how American traffic engineering is done.
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
Optimist! ;)
Anyway even crossing on these will see cars driving over them and I've been hit by cars on these crossings. I've been in cars where the driver has ignored the red traffic light at a pedestrian crossing, in fact the same one on the way to watch a film at a cinema and the same one on the way back.
The drivers problem was inexperience, and too interested in what the other passengers were saying, they wanted to join in the conversation and not pay attention to the road, and there are a lot of people whose attention dangerously fails when driving when they have passengers, but its not illegal, but using a hands free mobile phone is. Legislators and the Police are hypocrits!
That driver who ran two red lights at a pedestrian crossing got away with it because they were son of a British Police officer, Detective iirc, even though the pedestrian had to jump out of the way to avoid being hit.
But I swear, I am able to make myself seen to drivers almost immediately at this particular roundabout. Maybe it's the design, or maybe just my neighborhood's culture. Probably both.
Not only entering traffic, also traffic leaving the roundabout.
Which means this only works for low traffic intersections, since a single a busy pedestrian crossing can dead-lock the entire roundabout in all directions.
My city has a slight modification of this: the pedestrian crossings are about 3 car lengths away from the roundabout. This means crossing the road takes slightly longer for pedestrians here, but the round about has a "buffer" of three cars that can wait for pedestrians before the round-about starts locking up.
But really, for busy roundabouts, pedestrian overpasses are the only sane choice. Ugly as hell to look at, but easily more comfortable than underpasses.
They're usually not accessible, or very expensive to do so.
Also, why should the infrastructure be vehicle-focussed like you describe? There's no reason other than people are so used to it.
If cars create problems with traffic - cars should be paying the price of solving these problems - so it should be cars that have to drive over/under. Let pedestrians stay on the street level.
This is how it should be solved (example from my city, I walk there almost daily): https://maps.app.goo.gl/BFBK6B6Q6LULQtSa6
There's a fast road for transit on the overpass, under that there's a slower crossing with zebra and bike path. No problem for pedestrians and bikes.
And you know, I'm OK with that. There are plenty of other ways to get around my city, so if you want to do it in your own personal metal box at the busiest time of the day, then you can wait 5 extra minutes.
Pedestrian overpasses would look butt ugly and way exceed the city's budget for this intersection.
This can all be easily be fixed by designing roundabouts with pedestrians in mind. Unfortunately that doesn't seem to be the case in Australia.
> Australia: Crash reduction after roundabout installed: 74% in the casualty crash rate; 32% in property damage only; 68% in pedestrian casualty crashes per year.
> Netherlands: crash reduction at roundabouts: 73% in all pedestrian injury crashes; 89 % for pedestrian fatality; 63% for moped injuries; 30% for cycle injuries.
> Germany: a 75% decrease in average vehicle pedestrian crashes for 25 intersections converted from stop signs or traffic signals to roundabouts.
> France: less than 25% of serious injury crashes or fatalities at roundabouts; 38 fatal or serious type injuries for every 100 crashes at roundabouts vs 55 injury or fatal crashes for every 100 crashes at controlled intersections; crash frequencies 4 times higher at signalized intersections than roundabouts.
And more at:
An Overview Of Safety Effects On Pedestrians At Modern Roundabouts @ https://www.witpress.com/elibrary/wit-transactions-on-ecolog...
Australia's rules regarding roundabouts prioritise vehicle throughput rather than pedestrian safety. Our road rules give cars priority at roundabouts - pedestrians don't normally get crosswalks and must take their chances dodging through the traffic. This isn't a flaw with roundabouts, it's a flaw in how Australia has chosen to implement them.
Given the lack of crosswalks, are those roundabouts designed to be crossed by pedestrians at all?
> I wasn't able to access the paper you referenced unfortunately.
Here's an alternative: https://www.researchgate.net/publication/271423184_An_overvi...
The paper references the following source which I'm not able to access: https://catalogue.nla.gov.au/catalog/2717863
I have recently tried navigating the world, temporarily, with a mobility imparement, and boy does it change your perspective on things.
Why do I, as a pedestrian, have to go down and then back up, why is the guy sitting in a box with 200 horsepower not the one going up and down? Also car underpasses do not become a public toilet the way pedestrian ones do
Why are able bodied men waiting in a queue for an elevator?
Why does a train station in the middle of a spacious suburb have no elevator, no ramp, and no way to get out if your can't use stairs?
As an American it’s often surprising to me how many countries lack any analog to the Americans with Disabilities Act.
There is a clear difference between how quickly infrastructure for cars gets fixed, and how a simple ramp could be not installed at a train station for decades.
The only issue is when the roundabout is huge, and the alternative huge crossing would suck even more. Just make the roads smaller in general and pedestrians will be fine.
It of course cannot happen in car-oriented suburbs, where you a driver can't even expect pedestrians to exist.
While I have not visited the US extensively, I was very surprised when in California at how respectful drivers were with pedestrians, not just stopping for them, but stopping a few meters before the crossings.
Krakow was good as well, but not to that extent. In France, overall the rural part is pretty respectful, and the bigger the city, the worst it is (in Paris and Marseille, it's not great).
The absolute worst city I've been to in that regard was Naples, were motorists will not stop at crossings unless you actively step in their way.
So yeah, a lot of answers are going to vary drastically depending on what's the driving culture there. Universally motorists will stop at lights, because of that harsh possible consequences of running a light (getting T-boned), but stopping for pedestrians at crossings vary widly.
The law was changed to say that if someone is waiting in front of the crossing you have to stop(with fines for not doing so) and the behaviour has changed to what it is now - you are right, most Polish drivers will stop for you if you even look like you want to cross - but it wasn't like this not long ago.
It also caused a massive uproar across drivers, as if the sky was going to fall down if they have to stop for pedestrians - and yet, it's all fine.
So you know, maybe in US it also isn't a lost cause, maybe it could change for the better.
This can surely be remedied by having the crossings being raised, acting as speed bumps for the cars and providing a better crossing experience for the pedestrian (or cyclist).
I'm not entirely convinced that the lack of lights would inherently mean that roundabouts are less safe for pedestrians than a signalled intersection - roundabouts remove the concept of running a red, since a car by design has to slow down to navigate the roundabout.
Finally, as a pedestrian, I can cross a roundabout whenever I want to, no beg buttons or waiting for green required.
Do you have any statistics on their claimed lower safety?
And for large/busy roundabouts, cars will be in constant motion meaning there won't be gaps in the traffic flow for pedestrians to cross. If you try to cross [1] on foot at a busy period, it's not a particularly fun experience.
Of course, I'm not sure any road layout could make such a junction easy to cross, given the amount of traffic and number of lanes involved.
[1] https://www.google.co.uk/maps/@51.6428928,-0.2553056,17z?ucb...
This particular roundabout has a signalled pedestrian crossing on the southern side. Cars will get a red light (and pedestrians a “green man”) allowing them to cross safely.
But you’re right that there are too many UK A-roads and roundabouts that are a nightmare for pedestrians, lacking safe crossing.
I do so almost every day. Pretty much every roundabout has marked crossings with islands between the lanes, drivers slow down on entry so easily yield to a pedestrian trying to cross, and the crossing is about a car length out of the roundabout so on exit drivers have the space to both be out of the roundabout and yield to pedestrians.
Then again I’m in a country where drivers are generally respectful of pedestrians, especially on marked crossings most drivers will actively stop if they see a pedestrian getting close to a crossing.
This seems to not generally be the case in the UK, or at least in any of the large and small cities in England that I’ve spent time in. Except for zebra crossings (which are few and far between at crossings compared to most of Western/Central Europe or even the US/Canada) drivers seem to rarely stop proactively, if ever.
Coming from Germany, that difference in rules was always noticeable when going on a vacation to the UK.
It takes a long time for cultural change to happen, though. We have multiple generations of entitled motorists on the road at this point. And a carbrained prime minister.
For on near us it’s even worse as even though there’s an island to aid crossing the road signs are place in position that limits pedestrians view of the traffic leaving the roundabout
Fortunately they built a light controlled crossing a 100m further on
The worst is when introduction of it means I have to cross multiple crossings instead of one.
There is a train station about 500 meters behind the workshop, as the crow flies. I thought I would just drop my car off, walk to the train, head into the city.
It took 45 minutes of detours and a lot of sketchy sections to actually get to the train station. Lucky to have the suburban train for sure, but this particular old suburb had assumed everyone was in a car, and it simply hasn't put in the work to make it traversable to pedestrians. No sidewalks, lots of dead end roads and uneccessary fences. At one point I was staring at the station, with no way to get to it. Looong impermeable business parks etc. I just wasn't meant to be there by design.
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.
They actually work really well.
I'd love to see some of the things that generative ML could do in this space :)
Another advantage of the recursive design over a big roundabout is that it keeps traffic speeds slow, so collisions are much less deadly.
[1] https://www.apsed.in/post/conflict-points-at-intersection
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.
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.
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-... ).
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.
So I would suppose 'inside' and 'outside' were also considered relative to the kerb.
In practice, large multi-lane roundabouts in the UK usually have lane markings as you enter, with specific lanes for each exit. In general, so long as you were in the correct lane as you entered the roundabout, the lane markings should guide you to the correct exit and you shouldn’t have to do any filtering.
The problem seems to be that a lane that goes to two places is sometimes marked inconsistently with each of the two places - meaning you think you are in the wrong lane, when you are not.
If so, IMO they're the best thing that happened to roundabout design ever. You do need to choose a lane before entering but it's similar to how you'd choose a lane on a traditional two-lane roundabout. However, then you don't change lanes while on the roundabout, with ~zero visibility to the other lane while turning in a fairly tight circle.
This may differ across countries but around here you're supposed to: * pick the inner lane unless you're taking the first exit (to the right) * change to the outer lane just before your exit
which is about infinity times more stressful in traffic (you have very little time, it's hard to see the outer lane and the outer lane has right of way). It would work fine if everybody followed the rules but 1. they don't since it's unsafe in a tragedy of the commons sort of way and 2. then you end up with an informal turbo roundabout anyway.
A compromise that's becoming fairly common is a "soft" turbo roundabout where the lanes are divided not by ridges but by solid lines you can't cross only legally, not physically :)
We have both types here. And now that I think about it, the turbo trades a bit more stress on first usage or a lot less every time after that. While the standard 2 or 3 lane is always similarly stresfull.
We do have a partially soft design of turbo roundabouts with phisical deviders and designated places where you can change a lane.
That said, if I enter one I am already familiar with I'm perfectly fine. I guess it depends on who you are optimizing for.
And there's ample research showing that drivers respond to low-stress designs by going faster and not paying as much attention to things on the periphery. https://grist.org/cities/heres-why-narrower-streets-are-safe... or the illustration at https://i.pinimg.com/originals/e2/e0/dd/e2e0dd89a67fe1df1e6d... are useful.
Would you be so kind as to explain to me your thinking to the contrary, ideally with sources?
The rationale for these things was that they induce uncertainty in the driver, prompting him to slow down, pay more attention, and look more carefully. There are other schemes that were intended to induce uncertainty. The problem with all these schemes is that they depend on unfamiliarity to work; once a particular mini-roundabout is familiar, it no longer induces uncertainty.
On the ring-road around my hometown, there is a series of "hamburger roundabouts". These are large, multilane roundabouts, with traffic-lights as well, and with a lane-pair that runs straight across the central circle, for through traffic. These configurations have never become at all familiar to me; they always induce uncertainty, and I hate them.
If it's physically possible to drive over something, drivers will. A round concrete blob won't matter.
I don't buy it. Ending up forced to take an unexpected exit in a city triggers a lot of things for me and none of those are pedestrians:
- which lane should I be in for the quickest way back?
- what are the rules on the road I'm turning into? (this may be extremely not obvious if you didn't remember the sign for the road you weren't supposed to be on)
- does this road have restrictions that mean I actually can't be on it?
- is this going to send me on a toll road? (the joys of ending up on a single lane bridge which requires coins to cross and there's 5 cars already queued up behind you)
It's less of an issue for country roads, but being in the wrong lane in a place like this: https://maps.app.goo.gl/H8p1n8dcJ9D8epDG6 may mean you're doing a 30min detour to the same intersection and you'd better get it right this time!
The toll road example is fair, though I don't know the particulars of this in Australia.
I recently drove from Normandy to Amsterdam and halfway through Belgium I took the wrong exit and ended up adding 20 minutes to the drive. But it was fine.
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.
Haven’t seen one anywhere else.
Apparently there was one in Rockingham, Western Australia, says 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,... .
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.
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.
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.
Drunk drivers have launched cars into all kinds of random shit and places where you would not expect an accident.
Interestingly enough, a new roundabout was installed in my neighborhood. We considered something pretty to look at in the middle, but the city said no way. "Emergency vehicles need to be able to go through the middle at full speed". Meanwhile, busses have zero issues negotiating the circle at normal driving speeds...
https://www.youtube.com/watch?v=xTk_kPeA63c (turn the sound off, its just road noise) This is what happens when you go full bore into a big roundabout.
This kind of roundabout is used to join one large road to one or more small road (think two lanes going from 6-12 on the clock, with single lane road at 3 & 9)
In the UK, we don't normally have stop signs, as most junctions have clear rights of way (https://www.rac.co.uk/drive/advice/road-safety/uk-road-marki... see "Give way to traffic on major road") In suburban roads, roundabouts are often used instead of stop signs. It allows much freer flowing of traffic in both heavy and light traffic.
Just don't look up the magic roundabout, thats just fucking batshit, we only have one. The reason why they keep it is because there is literally nothing else interesting about the place.
Rude. ;0P
Actually there's another in Hemel.
Hemel, Swindon or England itself?
Do they? I guess it probably depends on the country. Here in Sweden I'm pretty sure you can drive in whatever lane you like (unless they're explicitly labeled). But normal lane-swithching rules apply ofc and, importantly, when you enter a roundabout you have to yield to traffic in all lanes of the roundabout, not just the outermost one.
That's how most of the multilane ones are are in my part of the US, and that's what makes them terrifying to me. It requires too much trust that the other drivers are going to do the right thing.
It also doesn't fully protect vehicles already inside the roundabout. My father got rear-ended once while inside a roundabout by a possibly distracted driver and the car was a near write-off.
The main advantage of roundabouts is traffic fluidity. When compared to intersections with stop signs or traffic lights, unless it is full you can often enter a roundabout without coming to a complete stop first.
This is the "truck apron". Virtually every roundabout in our town has one, and it's up a little curb to get onto it. A little too much for cars to sensible abuse, but a dirt motorbike gets over them easily. :) Also when it snows in people can't tell where the apron starts, so traffic tends to cut over it.
Cars going the wrong way is a non-issue. It is clearly signed how you're supposed to drive, and if they constructed it properly going the wrong way means you have to do a left turn of about 120 degrees. It feels so unnatural that you'll have trouble doing it on purpose, let alone accidentally.
Why? We are talking about people, who don't pay attention and drive through an intersection, the same people won't pay attention and won't slow down, let pedestrians to cross and do other silly things in the video.
> It is clearly signed how you're supposed to drive
I don't know where you live, but roundabouts near me have no signage of any kind. They are intersections with the center removed, on one near my home I've been seeing the same woman doing a left turn once a week (we seemed to have the same schedule so going there around the same time). Not to mention that many people don't pay attention to whatever signage you will put up, it's not a magic spell.
It's like turning right at a T junction. You simply can't do that at high speeds because you will flip your car. Most drivers have enough self-preservation to prefer slowing down over crashing their car.
And as for the self-preservation, running a red light on a normal intersection is doubly dangerous as you are risking both frontal and side collisions from both sides, if self-preservation is how roundabouts are safer then a normal intersection is doubly so (it is not, people who cause accidents are not guided by self-preservation).
Who is protected exactly?
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.
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.
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.
Not wrong, but traffic lights can be added to roundabouts as well ("signalized roundabouts")
* 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-S187704281...
And §8.1 Traffic Signals at Roundabouts:
* https://www.fhwa.dot.gov/publications/research/safety/00067/...
Also:
* https://www.access-board.gov/research/prow/literature-rounda...
too bad you can't go underground.
In The Netherlands there are several multi-level roundabouts, with one level for cars and another for bikes and pedestrians.
Somehow I'm reminded of those old pneumantic mail tubes interwoven with the fabric of the building...
Inside cites, those traffic lights in intersections were usually also semaphores for pedestrian crosswalks. So when you replace the intersection with a roundabout, you usually keep the traffic lights for the crosswalks alone. At the speed a car exits a roundabout, a non-regulated crosswalk could be quite dangerous.
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.
The alternative (at least from my experience in the US) is a 4-way stop, and is worse for all those criteria.
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.)
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.
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.
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.
https://www.google.com/maps/@42.3875777,-71.1422076,18z?entr...
this avoids complete deadlock until the entire roundabout is full of drivers who refuse to take any unblocked exit, while continually offering each the ability to do so
I don't understand how that helps. The problem is there are too many cars in the rotary, so no amount of not leaving the rotary will unblock it. It seems like you should not enter unless there's room to exit, but on some of these, you can't both see the exiting traffic light and safely merge into moving rotary traffic, so I don't really blame drivers who enter the rotary and find the light turns amber then red on them.
i could also imagine that anyone waiting behind someone who is deadlocking might have success sending a signal to the blocking process, unless they have committed to a non-reentrant exit routine
This can happen on routes where there are multiple chained roundabouts, that usually results in traffic coming at an even rate with no gaps in between.
Multi-lane roundabouts help when theres a clog downstream of the roundabout.
Roundabouts are also great if you have more than 4 roads meeting.
But yeah, in general roundabouts shine the most in low-traffic intersections that previously had lights. They make driving in those are so much nicer, drivers basically never have to stop.
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!
It is nice to not have to pay for replacement signals, or have to deal with power outages that kill the signals though.
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.
I'm confused by your comment that drivers merging into a roundabout are too distracted.
As a driver merging into a roundabout I find I have far less cognitive load. I only have to look for pedestrians crossing in front of me and cars coming from the left. When coming off the roundabout I only have to check for pedestrians crossing the exit I want to take.
At an intersection, all these checks are mashed together into. I have to keep track of all the cars at the intersection plus the pedestrians that may be crossing in front of me and the exit I want to take.
Drivers coming into them, who want to actually benefit from the roundabout and not just turn it into an awkward stop sign, are responsible for reversing the exit to lane mapping, then timing their approach to the intersection with an opening that will let them reach to their lane while maintaining a flow. If they can't manage to do that, of course they're supposed to stop and yield until an appropriate opening becomes available.
Inevitably, the designated pedestrian crosswalk is some 5-10+ feet prior to where the car would have to stop if it does need to yield while awaiting an opening.
Compared to a signaled intersection or a 2/4-way stop, where the pedestrian crossing coincides with a natural traffic stop, this basically means that approximately zero cars actually stop for pedestrians. Some are too busy to notice and others just don't want to have to deal with a stop and so ignore their responsibility.
I assume you must live somewhere else, where roundabouts are smaller and play some different role than here.
I'd argue that 1 lane roundabouts are far from decorative in residential neighbourhoods and are safer and allow for a better flow of traffic.
I'm slightly confused by your description, but it sounds like traffic lights for the pedestrian crossings would be a better option (which is often the case with the bigger roundabouts in the UK). Are the roundabouts you referring to like this one https://maps.app.goo.gl/xfxzDWTx4a7WPasUA or smaller?
Excepting for single-lane roundabouts, I find they require a much higher cognitive load for me.
I find I sometimes miss pedestrians waiting to cross from the right, because I must look left to merge with oncoming traffic and it's hard to look hard left and to the right at the same time.
At a signalized intersection, if all parties follow the signals, there's often no situation where I'm supposed to be looking in both directions for conflicts.
If I travel straight through the intersection on a green light, there should be no conflict with pedestrians (although one must always be alert). There may be a stopped or slow vehicle in front if the exit is congested. If an unprotected left turn is allowed, I must be aware of that potential conflict while I traverse the first half of the intersection, and if right on red is allowed, I must be aware of that potential conflict as I traverse the second half of the intersection. It's of course useful to be aware of potential for other parties to violate their signals, but look mostly straight but to the left for the first half and mostly straight but to right for the second half works for turns and red light violators ... and mostly straight is pretty good for pedestrians crossing against the light.
For turns, pedestrians are in the same direction you're heading, and often the same direction you're looking. Right on red is an exception, but one typically stops behind the line and looks around for pedestrians before crossing the line and looking for an opportunity to merge in.
For safety, pedestrian crossings should be moved away from roundabouts, where drivers will see them better, but then that increases the path length for pedestrians and acceptance is low.
What I've seen first hand in Ontario/Canada is that there's a huge increase in cognitive load simply because the roundabouts are still fairly new. Most drivers were never taught about them. They've just appeared. And they aren't completely intuitive for many drivers -- so their entry/exit isn't always ideal/safe.
For one, both entering and leaving the roundabout happens at low speeds, so there's very little chance of getting hit at high speed.
Second, the drivers are necessarily doing turns, so their blind spots move around quickly, which makes it easier to scan the area for pedestrians.
This is so true that it happens constantly at a roundabout in my neighborhood that has stop signs and white stripes at the pedestrian crossing, right before the merge. Even people in the right turn only lane do it.
have you seen the mini roundabout yet?
people kind of follow the rules but sometime cut over the middle - especially on the very small ones
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.
One went in here where people normally drive 60 mph:
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.
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.
Not quite sure what the exact history was, but they realized a few years back that they cost less and work pretty well.
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
but if they aren't common, so you need to construct it in a way that requires compliance, more space is required
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.
Checkmate atheists. Also my spellchecker is pointing out that kilometer is not a real word.
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.
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.
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.
- 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.
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.
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.
Mini Motorways also had them from the get-go, and they're much more robust than simple 3/4/5/6-way intersections.
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.
They decrease serious collisions.
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.
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.
Agree, when at or near 100% utilisation, its slower than a normal junction.
> you may actually increase the risk of collision due to negotiations about right of way happening every time a car can move forward.
That shouldn't be the case. Ideally you should always have priority from one direction (like in the UK, germany and the netherlands.) The generally rule is that when you come to the round about, if you see someone on your right(in the UK, left everywhere else I imagine) you stop and wait for them to drive past.
> two or three lane roundabouts with complex exit decisions you need to make on a split second
The driving exam will test you for this in the EU. The lane you chose is directly related to where you need to exit. If you are going straight over, or less, then its the outer most lane. Anything more than 180 degrees you take the inner lane. Exceptions will be clearly marked in both floor markings and signs well before entry.
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! ;-)
Same we know red light means stop. You make up a rule.
In Australia anyone from the right has right of way.
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.
In a 2 lane roundabout both lanes should be free before moving into it.
I mean, you can't rely on stop lights either. I've seen plenty of people run reds. What do you do then?
Example: https://www.reddit.com/r/bayarea/comments/10pihgk/roundabout...
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.
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/dat...
Simple roundabouts are fine.
Fortunately, I live in one of the few US cities that really are bike-friendly, so 90% of the time I'm on a bike path that is physically separated from where cars go.
The right lane is only permitted to turn right or continue straight. So the pink car is not supposed to continue counter-clockwise.
The left lane is only permitted to go straight or turn left. Thus it won't run into the cars on the right lane.
A collision could occur if people don't follow the rules, much like everything else when it comes to driving a car.
- Slow the fuck down
- Slow the fuck down
- Expect--and tolerate--others to make mistakes
The end.
Roundabouts work pretty well for all but the busiest roads.
Roundabout with more roundabouts on it. Because.
Basically just a little ring road.
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... 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_Foun... .)
I think Cocoplum Circle might count as a roundabout? 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/pedestria...
> In 2000, the U.S. only had 356 roundabouts. Over the past two decades, that number has grown to over 10,000.
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.
So 59 000 roundabouts for half the population versus 10 000 in the US.
That's a deficit of 90% per capita :-)
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.
The us does not have loads of them they are few and far between
The feature itself is fine by me, but the issue is it confuses people because it’s too similar to a roundabout.
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.
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)
This is a planning issue not a roundabout issue
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.