This is oddly timely. I'm travelling in Europe at the moment and have been covering a lot of area with a lot of roundabouts where they would be signaled or signed intersections in the US. They definitely make traffic flow smoothly and I've noticed a few areas where they are used to eliminate dangerous left turns at places like parking lots, you leave turning right, hit the next roundabout to "uturn" then head back the way you wanted to go. As a traffic device they really have lots of different kinds of use cases beyond just an alternative for a 4way.
Where I grew up in a rural part of the US, we had one terrible 4-way intersection between two undevided highways. Over time they added lights, then experimented with different signaling systems, but every day it would back up for several miles in a couple directions, and add up to 30 minutes to some commutes. Then there were the inevitable accidents as people tried to rush it, making things worse all around.
They replaced it with a roundabout about a decade ago, the population in the area also has increased dramatically in those years as farms turned into suburbs, but the backup is entirely gone. Theres no need any longer to maintain lights and switching systems, and the accidents are almost nil. Nobody has died there in years. People complained at first because it was "weird" then they realized they were complaining at home a half hour ealier than they would have been, so they stopped.
They've since added a few more in the area and have even gotten very experimental with a double diamond interchange that's also done a lot of good. There's something in the water at the planners office. Seeing that transformation though and the immediate benefits has turned me into a lifetime fan of the roundabout.
I'm living in Germany, where roundabouts are very popular with planners recently. I would say they definitely have their place, but they are also overused. The (smallish) city where I live has a bypass road where for some reason it was decided to use roundabouts (I suspect the same reason why it has so many tight curves - not wanting to purchase too much land). With the result that using the bypass is not much faster than driving through the town, so barely anyone uses it.
Sometimes roundabouts are used to limit traffic speed, since you MUST slow down, while keeping the same flow (for the calculated traffic throughput). Maybe that was the purpose. Roundabouts are generally more expensive than intersections due to needing more land works and more land than a normal cross intersection.
Where I live some of the locals treat a newly-built roundabout like the Daytona Speedway. It's almost as if their mentality is that you must NOT slow down, and they won't hesitate to express their displeasure at you if you happen to be "in their way" going the 15mph speed limit through the roundabout.
I don't know if that was the purpose or just a side effect, but I would have thought that the purpose of a bypass is to provide a more attractive route than the one going through the town center (so motorists have an incentive to use it), and having to slow down at the roundabouts (along with the mentioned tight curves and the 60 km/h speed limit) completely destroys the attractivity.
drivers may interpret it differently, but flow is typically faster than stop&go, plus the illusion of "if you're moving you're getting somewhere" helps.
We love a good roundabout in the UK, however it can be taken to extremes. The Magic Roundabout[1] in Hemel Hempstead is basically a roundabout made up of 6 mini-roundabouts. When it was first built locals used to sit in the middle watching the crashes.
You're the 6th person so far to mention Hemel Hempstead; but it's a poor choice for a comment, because it's an extreme case. The normal and far more common occurrences of roundabouts in the U.K. support bane's point.
Indeed, the junction in the headlined article is a slight variation on a quite common U.K. junction type: the double mini-roundabout. We can point to loads of them, such as this one in Bridgeyate (https://www.openstreetmap.org/#map=19/51.457696/-2.462268) for just one random example.
All of the WSDOT's points, about how large vehicles traverse them and how they are shaped like that because the staggered junction or slightly askew cross-roads that they replaced has space restrictions, apply to double mini-roundabouts.
And as bane said, the research in the U.K. back in the 1970s when double mini-roundabouts were a new thing showed a significant reduction in accidents over the prior staggered junctions and askew crossroads, at less cost than enlarging the junctions.
So the response is not to perplex the United Statians with Hemel Hempstead, but to welcome them to the shiny new future of 1970s road systems. And perhaps warn them that by the 1990s the road markings will have become a bit worn and scuffed by all of the HGVs driving over the centre. (-:
Yep, in my city we have a roundabout with 4 cardinal directions, roughly aligned with compass directions.
The West connection is to/from highway, so it has most traffic. People arriving from North/East/South want to leave on the West. And this causes massive jams, as the constant supply of traffic going from South entry to the West exit (i.e. doing left turn, and passing all ramps) essentially blocks all the other traffic.
Roundabout are great, they increase safety of dangerous intersections. But sometimes a controlled intersection is just a better idea.
the UK has traffic lights on certain heavily used roundabouts - sometime the lights will be temporary and only turn on once the throughput hits a certian level
I believe that I've read that elsewhere. They allow for better and higher flow than an intersection, but have a weird failure mode at very high rates where the circle gets loaded and all directions thus stop.
It's rather that if there's a continuous inflow of traffic that usually doesn't take one of the exits, then all traffic coming coming from that exit doesn't get a chance to join the roundabout.
What usually happens is the roundabout gets traffic lights.
No, I got that from a materials road engineers made available publicly a while ago when I was interested in the topic. It had whole bunch of various trade-offs you can make with intersections in it.
The preference for 4 way stops in a country that otherwise prioritises traffic flow so much is really jarring. Traffic lights too to some extent.
About 5 years ago my wife an I were doing a California road trip. At one point on a relatively rural road -- I think it might have been Dry Creek road heading into Napa but cannae mind exactly -- we got stuck in traffic for around 45 minutes. We thought there must have been some huge accident or roadworks closing the road. But got the the end and nope... 4 way stop essentially letting one. car. through. at. a. time.
I distinctly remember exclaiming "why the f wasn't that a roundabout" after clearing. Funny that it is now one of my strongest memories of that trip haha.
4-way stops are bizarre to me having grown up in the UK where roundabouts/intersections with priority given for one direction are trusted and reliable traffic-calming measures.
I think one of the reasons a 4-way stop might be introduced is to improve safety where there was previously a 2-way stop (that people would blow through). I came across this in Canada recently. All I can say is the UK has drastically lower traffic-related deaths than Canada [0] and I think I've seen 2-3 stop signs in my entire life. I imagine North America's pedestrian hostility is a piece of this puzzle.
Don't get me started on North American highway interchanges. The UK's roundabout junction system is far superior, in my opinion.
Four way stops are common in lightly trafficked situations where the locals can't justify spending the money on anything but a few stop signs. For instance, the main street through a small town (<2k pop) might have traffic lights and maybe a circle for the one other major road it intersects, but where the two or three roads parallel to that intersect with other town roads, a four way stop makes the most sense. Most of the time a car gets to one, it will be alone. Since neither road is long and neither is expected to have fast cars anyway, a four way stop is the most natural and intuitive option way to sign it.
Four way stops are also common when two country roads of relatively equal weight intersect. There are so many roads like that, so many intersections, that the local government can't possibly afford lights or circles on all of them. If one of the roads is known to get substantially more traffic than the other than a two-way stop is usually used, but if it isn't obvious then a four way stop is the safe default. In these situations, pedestrians aren't a factor at all because the intersection is five miles away from a town and it's farmland on both sides of both roads. Virtually nobody is walking there, not even people walking their dogs (unpaved access roads are better for that anyway.)
I'm not sure why the four way stop "makes the most sense".
In Europe one road (perhaps arbitrarily) would be declared the main road, and the other road gets yield signs, or even just yield road markings (triangles).
If one is obviously a main road then it's a two way. If neither is, then it's a four way. If the intersection is lightly trafficked then there's not any reason not to make it a four way because it won't cause meaningful delays anyway. When a county has several hundred country road intersections that get a few dozen cars or less a day through them, it doesn't make sense to even spend time studying each one. Just throw up some stop signs and consider the matter resolved.
Or do what they do in the UK. For all of these, make them 'mini-roundabouts' which is literally a dot painted on the center of the road. You follow the rules of the roundabout without building one. Works just as efficiently as a four way stop with light traffic - actually more, since you don't need to stop if the intersection is empty.
Or, in the absence of any signage, it'd just be "right before left". Relatively common in the outskirts of cities where there isn't one road that has significantly more traffic than the other one.
No, that’s not the same. On a 4-way stop you have to completely stop. Also how I remember my year in the US (I’m from NL) is that the first to reach the stop has right of way, not the “left” one. But I might be wrong on that last one? Didn’t have a drivers license at the time (but was surprised - and turned off from - 4-way stops).
90% of stop signs in the US/Canada should actually be yield signs. Stop signs are reserved for "dangerous" intersections, ie spots where a driver can't safely see or make a decision without first stopping.
Throwing a red octagon at every single intersection of two roads is lazy and absurd. It encourages people to break the rules (just run the stop sign) and cause accidents (zone out, stop and go without actually looking).
There's a T intersection in Mission BC that has a stop sign that (for people turning right) should be a yield (at most) because to the left is a one-way after the intersection eg no one should be coming from there :) but the problem is it's single lane and people making a left there should stop.
When turning right, I and a lot of people barely bother slowing down. It's always a bit frustrating when someone does what the sign (and the law of course) says when the don't need too from a pragmatic point of view :-D.
Funny, I live in the US and I treat about 90% of stop signs as yield signs. My ex-wife would complain about it to me all the time as if I’m doing something wrong, but I never stopped lol
I like 4-way stops as a pedestrian because I can actually cross the road there. With roundabouts it's impossible to cross without asking really nicely or risking my life. US drivers do not stop for pedestrians so crossing that kind of infrastructure is often taking your life into your hands.
Roundabouts should have only 1 direction you need to look at to cross. You don't have to watch 3-4 different directions like at a 4way stop.
That said, if there's a huge bias towards cars coming from one direction (or out one direction), that can be very difficult to cross. And it has impacts on the roundabout's throughput too, and means that a roundabout might not be the most ideal. Similarly to how a roundabout that gets backedup into can fail catastrophically (you have to make sure there's negative pressure!)
> It has impacts on the roundabout's throughput too
For these use cases there's the turbo roundabout[0]. Depending on how you design it you can give certain directions slightly more priority, though they don't solve the pedestrian issue either.
I live in the US now, but originally from Ireland. My least favourite part of US road infrastructure is the 4 way stop. They are just not good compared to a roundabout. Half the time the only way you can tell it’s an all way stop is by looking for the back of the stop signs on the perpendicular road.
With a roundabout, you only have to look in one direction, and if it’s clear, you don’t even have to stop.
Online I see this mentality that roundabouts are great no matter what and it seems really strange to me. It really depends on the design of the roundabout and the traffic conditions. Where I grew up there are a lot of roundabouts, but many of them are so dangerously designed I started actively avoiding them. It’s not that you can’t poorly design a four way stop, but it seems to be much less common, for whatever reason.
I see people complain about roundabouts with traffics lights and how it negates some of the reasons for the roundabout. The thing is, these aren’t just put in for fun, usually they’re in areas with extremely heavy traffic where merging can get extremely difficult which leads to long backups (or in cities, accidents that can shut down traffic).
Roundabouts can be great when used well, but they’re hardly the silver bullet that online discourse often portrays them as.
They absolutely are. Even if they don't prevent all collisions, they turn T-bones into glancing hits and so save a lot of lives. The worst roundabout beats the best 4-way stop any day of the week. Sometimes there really are easy answers.
> The worst roundabout beats the best 4-way stop any day of the week. Sometimes there really are easy answers.
Maybe you haven't seen the worst ones, then. For instance, one by my house had traffic lines which gave people the wrong impression about the right of way within the roundabout, leading to every vehicle treating driving like that. I actually drove like that as well for a long time - when you're spending every day driving the exact same way that the hundreds of other cars surrounding you are driving, and the lines on the road suggest that it's correct way to drive, it's easy to mistakenly think this is what you're supposed to be doing.
Then it hit me one day - this isn't how right of way works in a roundabout at all. I talked to others in the area, who were surprised when I brought it up. That's what the lines implied, that's what everyone _did_, but that's not how it was supposed to be used. Everyone was driving through this incorrectly. And it was a major roundabout, that had some of the heaviest traffic in the city.
Maybe it didn't matter because everyone was driving incorrectly, which worked most (but not all) of the time? But when it wouldn't, the accident would be a T-bone, so we can't say that roundabouts eliminate those.
Years later someone in the city seemed to realize it, and changed the design of the roundabout. It's better now, but there are still a few areas they overlooked that have the potential to cause accidents.
I'd really like to know where this was or see some pictures of it. It's almost inconcievable that something designed like a roundabout would be more dangerous. It might indeed cause more accidents due to the kind of confusion you describe, but at the very least the angles and grading should lower speeds dramatically and result in fewer deadly accidents.
It's set up like this - busy avenue with lanes (left to right) 1, 2, and 3 enter into roundabout with circles (inner to outer) A, B, and C. The problem is that half way around the circle, where the avenue continues, A, B, and C then have lines indicating that you can either continue on the circle or move in a perpendicular direction to the circle and exit back such like this A -> 1, B -> 2, and C -> 3. And that's what everyone does. The problem is If someone from C is going around the circle, they're going to t-bone anyone going A -> 1 or B -> 2, and there's no moment to prepare because A or B is going to be suddenly cutting in front of them.
Or to visualize it another way - if you can image those intersections where there are two right turn only lanes, and one lane to the left of them that's right turn or go straight. Now imagine if all three lanes were right turn or go straight, and everyone made right turns - but if someone in the far right lane is going straight, they're plowing into the cars turning in the other two lanes.
After years they eventually fixed it and made the two outer circle lanes right turn only, which is what they should have done at the beginning. But even there they screwed up, because there's a street that enters the circle right after the right turn only signs, so if someone is entering from that direction and isn't familiar with the circle it's possible for them to ram into the other cars.
PIT maneuver is not a T-bone. Even if you cut across a lane (from C to A) there won't be enough of lateral velocity to make it potentially deadly. That's one the of the major points of roundabouts.
I live in an area with many A, B, C as you call them. Assuming we're going backwards, where A is right most lane, with these three lane roundabouts it's always A can only turn right, C an only turn left, B is for going straight, but can also turn right or left.
There are variations on this, sometimes, B can only go straight so that C can also go straight. C can also be used for a fully controlled U-turn. In fact, C is has the markings such that one can just go around and around and around forever in if one chose to do so.
All of the roundabouts here have overhead signage leading up to them that indicates which lanes are for each direction of travel. There are also lines on the roads themselves have solid and dashed lines. Never cross solid lines, optionally cross dashes. We get snow so lines aren't always visible.
I've been through many different roundabouts countless times and there is occasionally someone that doesn't get it right but the traffic is moving slowly enough that it unusually only leads to honking.
One strategy is to watch the faces of other drivers, people will be looking in the direction they will be turning.
Just because you drove wrong does not make the roundabout bad. That would require you to compare accident numbers from before and after. I’m fairly certain the stats lean in favor of even terribly designed roundabouts.
> Just because you drove wrong does not make the roundabout bad.
You seem to have misread my post. Everyone drove wrong. I seemed to be the only one to notice it, and started avoiding that roundabout, because driving with the correct right of way rules during busy times would lead you to t-boning another car. Other people I talked to said "no, that's just how you're supposed to drive on that roundabout" (it wasn't, and the signage was eventually updated many years later).
If _everyone_ is driving through it incorrectly doesn't make it a bad roundabout, than I suppose no roundabout can be bad. If it's always the fault of the drivers and never the design, you can't really say 4 way stops are any worse in this regard either.
I think you missed my point due to me saying something about driving through the roundabout incorrectly. My apologies, that was entirely besides the point.
I’m trying to say that everyone driving through it incorrectly is not a great metric to judge bad roundabout. If everyone does it wrong and it’s still safer than a regular intersection, then is a success.
Of course I don’t know the numbers involved, so I can’t say if that’s the case here.
I think they're a bad design as they encourage drivers to go fast with the sweeping corners etc. Ideally, a roundabout should be designed to slow traffic joining it to reduce collisions and their severity. Trying to keep vehicles moving quickly at junctions is just asking for trouble.
The one I linked to in Fairfax County VA also has lights, though it might not be obvious from the aerial view. It's really a disaster of traffic engineering. It's probably the most complicated intersection I've ever driven through.
You can actually screw them up: by our house (in California) they replaced a 4-way stop with a roundabout with no signaling on 2 of the ways, and a stop on the other 2. An absolute disaster, as the 2 ways without the stop assumed they had the right of way over people already in the roundabout.
After the neighbourhood complained, it's now a roundabout with 4 stops (not ideal, but not dangerous either).
This. If it's not the case that all entrances have a Yeild (what we call "Give Way" in the UK), it's not a normal roundabout.
The feature that seemed to be missing from the roundabout in the original post was any kind of signage. Normally in the UK, roundabouts have a sort of map view as you approach them, then on the islands are signs telling you where to exit.
I can confirm these are dangerous. There are several of these in Berkeley and I got knocked off my bicycle on one of them for exactly the reason you describe.
I am from the UK and it makes me wonder why road design in the US is so bad. Just one minute of thinking about this as a lay person would reveal the problem with the design.
Is there some structural reason in the US that would cause it? Perhaps some lack of standards or approval process? Perhaps iteration speed is slower so they don’t get better? Some other incentives going on?
My personal hypothesis on this is that the worst 5% of Americans is likely both dumber and more sociopathic than Europeans, and the behavior of the worst drivers is what creates a lot of traffic and road accidents. If that is the case, you will not have the same kind of design that works in a high-trust, more cohesive society.
What should I imagine when you say roundabout with 4 stops? Isn’t that just an intersection that looks like a roundabout without functioning like one (entirely negating the point)?
I guess drivers just don't realise they need to slow down or give way to anybody unless there's a stop sign, traffic light or they're turning into a different road.
Surely drivers know what Yield means though right? I guess the US might need yield signs at a roundabout given not all drivers will get the basics of how they work. There should never be a stop sign on a roundabout, the whole point is you're supposed to be able to keep going without stopping at all if theres nobody coming round it.
No easy answers, no solutions only trade-offs. Perhaps better for safety, but they makes crossing as a pedestrian longer and harder. And while intersections designed for roundabouts can be pretty smooth, retrofitting undersized roundabouts into intersections designed a 4-way makes for ugly and difficult to navigate messes.
I like them, but it is a mistake to blindly install them anywhere possible.
What's wrong with mini-roundabouts? We've got lots of them here in the UK, mainly in residential areas and I don't see the issue with replacing a 4-way stop intersection (U.S. style) with a mini-roundabout. All that's needed is to remove the STOP signs and splash a bit of white paint onto the road to mark the mini-roundabout. Optionally, build up the mini-roundabout to make it harder to drive over.
In most of the world, unless the intersection has pedestrian features (like traffic lights with green men or islands with pedestrian waiting areas), it's better to cross the road away from the intersections. Then you only have 2 directions of traffic to worry about. AFAICT, in the US, crossing away from the intersections is illegal in many cases.
When Cycling and approaching a roundabout move to the middle of the lane and follow the same routes as a car. Yes you slow the cars a bit but they are supposed to be going slowly anyway. If you don't want to do that, you can get off your bike and cross as a pedestrian would.
Roundabouts not good for pedestrians and cyclists. In London we’ve been replacing roundabouts with other types of junction to improve pedestrian and cyclist safety.
We don’t have four way stops though so instead it’ll be min/maj junction or traffic lights.
This is only true of typical UK-style roundabouts which are designed for motor vehicle throughput.
It’s extremely common in the Netherlands to replace crossroads and T-junctions with roundabouts to improve safety, but Dutch urban roundabouts are designed with safety as the main priority. This is achieved through single lanes, sharp entries, limiting forward visibility, and pedestrian and cyclist priority (via what are effective zebras).
We should absolutely be deploying these where we can, but they do take up a lot of space relative to their traffic throughput, and are only really suitable for a fairly narrow range of traffic volumes.
NL seems to quite commonly have this kind of physically large but medium traffic suburban junction, but outside of Milton Keynes and the outskirts of some towns that got heavily developed in the 60s, it's hard to see many places where we could just drop it in.
> That the Dutch roundabout, including the cycle tracks all around it, can be built in almost the same space of a traditional junction is the reason why so many are being converted.
In some cases, I see roundabouts used in places a stoplight would be much better. It isn't roundabouts vs 4-way stops, its roundabouts vs a whole bunch of other options.
My experience driving in rural France was that nearly every intersection was a roundabout and it slowed things down dramatically. Many, many times I was the only driver within sight. Surely one of the two directions is more used and a couple of putting stop signs the other way would make more sense.
Roundabouts are great sometimes, but they aren’t a magic bullet.
That said we have a nasty intersection in the area on a highway that they’re going to redo, which absolutely no one could have foreseen 10 years ago when they first put it in.
The 3 options were j-turn or roundabout soon, or a full on overpass type system in another 10 years.
J-turns are awful, so while that was their first idea it was thankfully put down. It would have been even worse as it leads into a school and most buses in the area would have needed to do U-turns on the highway, as well as new teen drivers. In Minnesota.
Old people complained about roundabouts because even though they’re used quite a bit in the area apparently they don’t drive and don’t understand them.
So, 10+ million dollar overpass for a town of 2,000 it is, in 10 years. Let’s hope not too many more people die before then, eh?
That it slows things down significantly is a feature not a bug. Rural roads have a lot of accidents. In my country the most fatal ones. There are two main reasons for that: speeding and fail to yield. Often combination of the two.
Roundabouts solve the issue as you have to slow down before the intersection.
> My experience driving in rural France was that nearly every intersection was a roundabout and it slowed things down dramatically. [..] Surely one of the two directions is more used and a couple of putting stop signs the other way would make more sense.
Yes, that is by design. Slowing traffic down, also in relatively low-traffic areas, is one of the use-cases for roundabouts in France. Mostly around villages and/or industrial areas.
Try driving in England, rural or otherwise, and you'll see our current trend of adding traffic lights to roundabouts.
If you think roundabouts slow you down (they don't really), just wait until non-rush hour at one of these "roundabouts" when you're the only car waiting on several sets of red lights, or during rush hour when the lights have failed and it's totally gridlocked where traffic simply cannot pass.
To be fair, most of the gridlocked traffic is caused by drivers not understanding that they shouldn't enter a yellow box junction until their exit is clear and similarly, they shouldn't be nosing out onto a roundabout when their lane is already full - that's what tends to cause the issues.
True. It's in the Highway Code. Then again, so is 'move quickly past the vehicle you are overtaking, once you have started to overtake. Allow plenty of room. Move back to the left as soon as you can but do not cut in'. But you wouldn't know it driving on UK motorways.
You can mess roundabouts, but it requires a sever lack of competence that we rarely see TBH, and it can be progressively improved (signage, better visibility, lines etc)
I'm with you on how some will still be dangerous, and can require traffic stops. But it's still better than going back to a plain stops IMHO, and it's usually in portions where it was already dangerous before putting in the roundabout. In practice I've never seen a reversal of a roundabout to get back to a plain intersection.
I don't think most of the ones here could be easily reversed, for what it's worth. The streets were designed with them in mind, so they're usually at the exact spot where 3-5 different roads intersect.
The number of bad roundabouts is pretty common here, though. But it wouldn't entirely surprise me (based on other things I've seen) if there was a level of local incompetence that went beyond the norm. You're right that they can be improved, but (I mentioned this in another reply), sometimes that takes years or decades for whatever reason (and even then, they don't fix all of the issues).
The biggest problem with a 4-way stop in a busy city is that it can be easy to miss the stop sign which makes it easy to cause an accident, which could kill someone.
No matter how terribly designed, it's hard to entirely miss a roundabout. You basically need to be incoherent.
Yep. Canada suburbs here. We're starting to see roundabouts used more often for what would be higher traffic four-ways or inconvenient lights. They're great, both as a driver and as a cyclist. Lower conflict risk, simple rules to proceed.
IMO all smaller 4 way stops should become what I've described as trash can roundabouts. Small island to circle around. So much better than stop signs.
Signage exists. Plus the vast majority of times painted ones are used in areas where almost everyone on the road knows how it works, and within minutes of it snowing a very clear outline of the path cars have taken would make it abundantly clear what the process is.
Roundabouts are engrained into UK road culture, you'd seldom find a driver in the UK that cant figure out how one works, even if they may not have great lane discipline on the larger ones.
People are generally driving significantly slower in snow though, so the need for a roundabout is lessened. And you can also install signage indicating a roundabout is there.
A roundabout requires signage in any case. At least in all countries I've seen one so far. Otherwise it's not a roundabout and may even have very different rules.
The signs preceding a UK mini roundabout would not be.
And it rarely snows in the UK these days. And I would hope you would be driving extremely cautiously if there were snow on the ground (in the UK) as it's such a rare event.
I'm not sure what your point is as roads become invisible when it snows. Is there something unique about a mini roundabout versus any other road markings? It's almost as though you're implying that drivers will speed towards a multi-road junction when it's snowing and not bother to slow down, despite the signage.
In Seattle, we have trash can roundabout (really just round traffic calming islands, we don’t consider them roundabouts) and stop signs at the same intersections.
Unfortunately, most drivers I've observed in the US seem utterly confounded by roundabouts, particularly the yielding part. The roundabouts I've experienced - there are several where I live - are mostly single-lane, and are still very nerve wracking to drive around because other drivers behave very unpredictably. Then again, I also see folks struggling with (or intentionally ignoring) queuing for 4+ way stops.
That said, I agree with your points, and I personally prefer roundabouts to queuing stops. They flow so much better, and really help to improve congestion/bottlenecking.
The state put in a roundabout in my town last year on an a relatively busy county road with a turn towards a new elementary school. While a lot of people had big opinions on it before it was built they figured it out pretty quickly, to the point that it's a non-issue. My manager, who is kind of a crank, noted the first day he used it to drop his kid off that he didn't expect it to work but it ended up being really smooth. In my experience drivers now are more consistent at navigating the roundabout correctly than at following right of way at any of the 4-way stops in town.
Truthfully I'd say about 60% of drivers in the States have no business behind the wheel of anything, much less the mammoth pedestrian-devouring SUVs and trucks we're such fans of. It is shocking how BAD it is getting.
I think COVID really kicked the enshittification of drivers here into a new realm. That spat where driving tests were suspended in so many places and driving school wasn't workable has let a couple years worth of drivers onto the road who had almost no practical instruction, and it fucking shows. And it's not like most people were good before that. For the vast majority, driving is a chore and you can tell that by the absolutely bare-minimum efforts put into it.
> With a roundabout, you only have to look in one direction
When being taught how to ride a motorcycle, one of the lessons is a series of extra checks that you're not taught when learning to drive a car. These are known as lifesaver checks.
Entering a roundabout is a left turn in Ireland (right turn in right hand drive countries) so you would check over your left shoulder to make sure nothing was on your left. This is performed after doing a normal right and ahead check for traffic already on the roundabout.
I have never caught anything with a roundabout lifesaver (I have in other situations) but I can see how it's useful on roundabouts with multiple entry lanes, or if something like a bicycle had appeared on your right.
I've lived with both roundabouts and 4-way stops, I think they both have their places (and also if you haven't lived with them both are hard to pick up on) 4-way stops are great for slowing traffic in neighbourhoods (you have to stop at every block), roundabouts better on faster mid level roads
There's one four-way stop I pass regularly in Ireland [0].
I suspect there isn't enough room for a roundabout, and we also don't tend to construct roundabouts on hills (I'm not sure why they're any worse than other junctions there). There's a steep gradient going uphill from South to North.
Normally it would be a two way stop, and I sometimes wonder why that wasn't chosen here. Likely because visibility is bad (trees, walls, curves - it's worse than it looks in the satellite image) and cars coming from the east and west can't completely tell that it's safe to enter the junction.
A four-way stop would be confusing for me, those don't exist in my country as far as I'm aware. I was also thought that a stop or yield sign means I'm on the side road and the other road implicitly has priority.
It can get complex for us here as well, one example is when the priority road doesn't go straight through the intersection, eg. L-shaped main road, and then the other two have a stop and a yield sing. A lot of people where I live wrongly think that the yield has priority over the stop sign, it's a widespread misconception (I'd say more people believe it than not). In reality the priority to the right rule applies between side roads and the only difference between yield & stop is that the stop sign requires you to actually stop the vehicle.
And then there are plenty of T intersections in smaller towns and villages where people assume the road going straight is the main road, even though there aren't signs and the priority to right would apply. I guess drivers mostly rely on habits and intuition.
> Half the time the only way you can tell it’s an all way stop is by looking for the back of the stop signs on the perpendicular road
The other side may have a stop sign, but are they stopping?
Its sort of useless to know if you have the right of way or not when you drive defensively. Just assume you don't and only go if you actually see someone yielding/preparing to yield to you.
I am not sure if you are disputing that such things exist, or making a sarcastic comment, but I know of at least one location where they literally put in a round about, that originally had normal roundabout entrances, but then someone complained a dug up some rule that said that anywhere a county and a city road met, there needed to be a 4 way stop. Now obviously this rule was intended to just make sure that such intersections were controlled, and was probably written before the US had really thought about round abouts as an option and a roundabout met the spirit of the rule just fine, but nevertheless it was a rule, and so they added a stop sign at each entrance.
So, if you were making a sarcastic joke: then yup, they managed to convert a round about into a 4-way stop with a (giant, view obstructing) island. But if you were arguing that no one would do such a thing as put stop signs at the entrances to a round about, I regret to inform you that they absolutely would.
Also, I'm now curious about the existence of "4-way stop with an island". Why would someone build that? It seems strictly worse than a regular 4 way stop.
Too many people remain at the stop sign until the roundabout completely clears, so it becomes an excruciatingly slow 4-way stop. And there's not much traffic there.
A few miles from that one, there's a high traffic roundabout that works very well. The heavily used right turn lanes are divided and don't enter the roundabout. There are very clear markings on the ground. And there are yield signs at the entrances, so people know what to do. Traffic flows great through it, with the heaviest direction of travel naturally getting more throughput.
They don't have to understand roundabouts specifically, there is supposed to be a yield sign when entering a roundabout - do they not understand the yield sign?
Or two near me have traffic lights very near (1/4 block or so) from the exit, meaning that traffic will inevitably back up into the roundabout, locking it up.
> Half the time the only way you can tell it’s an all way stop is by looking for the back of the stop signs on the perpendicular road.
Your state is doing it wrong then. Almost every four way stop I've ever seen in the US has a little sign beneath the big octagon which says "4-way".
Anyways, I have nothing against roundabouts. But I do have issue with some states (looking at you, Wisconsin) which are obsessed with tearing out perfectly good stop signs (as in, it's a low volume intersection or it's only a two way stop with a highway going through) and replacing them with roundabouts. It's just a waste of taxpayer money.
That being said that looks like a pretty decent and standard setup for a set of roundabouts, certainly wouldn't look out of place in the UK and would be vastly superior to a whole host of stop signs and red lights. It probably could've been simplified slightly by turning the two middle ones into one long oval roundabout, those are pretty common on motorway junctions in the UK.
I was going to make the same point. With that slight modification it's an everyday thing for many U.K. drivers and fairly easy to navigate when one is used to such.
That is a good way to have an accident - I know since I've done it. While "looking one way" on a USA counterclockwise roundabout you are looking left to see traffic already on the roundabout and if clear you go and run smack into the back of the vehicle ahead of you who for some reason stalled or hesitated or just judged the traffic differently. However it will be a low speed accident.
As a general rule, one should be looking in the direction in which the vehicle is traveling.
It's easily done though, if rushing, or if the vehicle in front pulls away slightly but stops again.
Apparently I'm sticking my neck out here, but it really doesn't seem that hard. Overhead, I can intuit the path I would take, and if I imagine it first-person, it seems even more obvious.
It's frustrating riding with certain other American drivers in other countries. I've met numerous folks now that seem upset that they have to actually pay attention to their driving and the traffic. Meanwhile I'm horrified that they're apparently just ... completely on auto-pilot in the US.
No, you're definitely not the only one who likes them. Some folks complain about them when they first go in, but they tend to figure it out.
WSDOT has been encouraging them for a few years now, and my town has several new roundabouts as a result -- and lots of other cities across the state are using them. They've made navigating those intersections way easier, reduced traffic "waiting times", and generally improved safety versus a lighted intersection. I'm glad they're continuing to find ways to make them work.
It seemed when I was growing up in NJ, the state DOT was taking out the giant roundabouts that they were famous for, and now in Washington, they're having a huge resurgence.
Huge roundabouts are very dangerous; the safety factor in the modern ones WA installs is that they are tight and slow, which reduces the severity of any crashes.
It also does not help that NJ is the only state in the US that does not have a consistent rule about roundabout traffic priority.
I agree, Washington does seem to at least aspire to better roundabouts than some places I've heard of. The one rule I see to be truly necessary is "yield to oncoming traffic from the left."
I still get confused at the big roundabout in Kent, after coming off Highway 167 at Willis Street, but most others I've encountered are fine, despite the drivers who still want to stop before proceeding onto them even when there's no other traffic.
I'm ok with most roundabouts. However, there is one near me that everyone complains about. There are 3 of them right in a row, but even that isn't the main issue. There is one with 5 places to turn out, which is relatively small and confusing. If you get it wrong it dumps you out on the expressway and it's an almost 9 mile trip to get back to where you originally wanted to go with no other option than to drive the 9 miles. I have yet to talk to a single person who hasn't made this mistake at least once. A little "oops" road to connect the expressway on-ramp with the road people intended to take would go along way and save hundreds, if not thousands, of wasted miles each year. Many people avoid the area completely because they don't want to deal with it.
Don't the exits have signs to say where the exit takes you? In Europe they'd be labeled, and highway onramps will have a different background color to indicate a highway..
Also, keeping your navigation display "north up" is much better than having one that will probably be laggy in a roundabout, confusing you on which exit to take.
If all else fails, look at the signage; I remember driving and a passenger not sure if the roundabout exit I was taking was correct, I said "Well there's a big sign there that says this way to our destination."
I think part of the issue is that it’s multi-lane. So if you’re in the right-lane to go to one road, and miss it, staying in the right-lane forces you onto the highway. If there is a car in the left lane you can’t get over to avoid it without causing an accident, or stopping, which would backup the whole circle and also risk accidents. So you end up paying the 9 mile tax. There is no way to miss your turn and easily recover.
Indeed. I've seen a number of stuffed-up multi-lane roundabouts in the States.
I've also seen a trio of 3 of them be adjusted (by changing lane markings and signage -- nothing of grand expense) in a way that was much more sensible and easier to follow than the original design.
It seems to me that a lot of the issues with them could be eliminated by having a bail-out path that is both safe and acceptable.
Logically, it seems like this ideally means providing the opportunity to simply go 'round again and do it over.
Or where that's not possible and there must be a lane with an irrevocable default exit, then: That exit should be low-cost and provide an opportunity nearby to safely stop and spend as much time as it takes to re-evaluate a second attempt.
It should never dump a driver into an unexpected 9-mile-long Pavlovian clusterfuck.
I like the German roundabouts that have 3 lanes at each entry. The furthest left takes you to the 3rd exit (left hand turn), the middle takes you to the 2nd exit (straight ahead), and the right hand lane takes you the 1st exit (right hand turn).
The lanes are painted to "spiral" so that if you take the furthest left hand, by the time you get to the 3rd exit, it's the outermost lane.
Spiral roundabouts are very common all over Europe, including the UK. They take a little getting used to, but once you realise your drivers side wheel just needs to stay the correct side of the white line, and the white line will take you where you need to go, it's all good.
They do, but I’ve easily made that mistake. Most recently near Joigny I exited too early twice. Each was easily recoverable since I could simply go back around at the next but while it’s on me and a local would never err it did happen.
Led to quite a bit of ribbing from the passengers so perhaps this is a PEBKAC after all.
I genuinely cannot read that roundabout from overhead, and I am not a person who has trouble with roundabouts. I think it would benefit greatly from an explanatory diagram. I do hope that it would be more obvious while on the ground, like you said.
Unfortunately, it's not. Driving from right-to-left (in the first picture) requires drivers to enter the roundabout twice, then leave once. Judging by the amount of vehicle debris generally present and the additional "Yield" markings and signage that have been added to the second yield point since the construction was completed, it's been confusing from the ground as well.
I'll take a traditional cross with traffic signals or stop signs on all sides, it's simple and effective.
Roundabouts are a waste of space, disrupt traffic, and take more brain processing than I care to afford if I can help it. This particular example isn't even round.
I vastly prefer roundabouts, with a single exception. If traffic is heavy and dominated by the same entry and exit points, it can be hard to get a turn if you're coming from the side. Our nearest roundabout is this way.
I once saw a roundabout with stop signs. I assume it was an attempt to address this situation.
You do, but that means there is no roundabout when you need it the most.
The problem occurs mostly when the dominant flow is given multiple lanes.
A fairly common solution/workaround is blocking the view of the approaching traffic, forcing it to slow down. But again, this doesn't work well on large roundabouts that allow people to speed up to of 30+ mph.
I used to go to work past one like this. They replaced a light where you would always eventually get to go with a roundabout where the 99% of traffic going north/south meant the other two ways were effectively not part of the traffic network for a few hours a day.
I think the problem is not that they're impossible to figure out but you have about 2 seconds from when you see the sign to when you're entering the double roundabout.
We have back-to-back round-a-bouts in Chattanooga (153 / Lake Resort / Access) which have two loops (concentric inner & outer round-a-bouts)... that can be quite confusing for anybody unfamiliar with the local pattern.
I would do everything possible to avoid this UK Round-a-bout — nothing Magical about it having three concentric lanes just in its inner loop! =P
Ours is much simpler, with a round-a-bout on either side of a regional highway. One of the difficult parts about it is everybody is already jacked the fuck up (on account of 2 of the 5 input/outputs being extremely steep grade to enter/exit a river-crossing, with speeds averaging 65-70mph ["55mph" posted, oklol).
Oh, I've re-read and you just mean there are two fast paced roundabouts that are close by and they both have two lanes around them.
That wouldn't raise an eyebrow here in the UK, it's very normal for highway junctions to have on/off ramps that end in 2-3 lane roundabouts, one each side of the highway.
> In terms of brain processing, you get used to it and it becomes second nature. It is a skill.
Yeah, if my driver’s ed class (both content and classmates) are any indication, a four way stop is anything but intuitive or brainless.
There’s a lot of time spent covering the right of way order, and a lot of people failing their driving test on it.
Roundabouts are only disruptive because of a lack of familiarity… the only way to build that familiarity is with practice. Sucks that you have to learn a new concept after a decade or two or four ~~in the industry~~ on the road, but seems necessary for progress.
If your stop signs don't disrupt traffic then they're not working properly. Roundabouts are designed to efficiently weave traffic streams together instead.
Your opinion here is at odds with the record for higher traffic throughput and better safety for roundabouts. They are better in pretty much every way, for appropriate situations.
Here the situation is uneven road size, through traffic on the highway and odd angles. Perfect roundabout application.
Roundabouts are faster, safer and more convenient. It sometimes needs additional traffic lights, since heavily congested roundabouts lose their effectiveness.
The picture of the roundabout from above at the beginning of the article is extra confusing because it doesn't have the final lane markings yet and the ones you can see are misleading.
The (presumably) final markings[0] make things less confusing.
I was looking at the markings that are there, and they made it seem like traffic approaching the roundabout would have priority over traffic already on it.
What the hell is that "dump truck with trailer" on a really long connector at 3:50? Is that a thing in some parts? How does that navigate almost any kind of roadway safely?
They're called "pup" trailers [1] (example photo [2]), and the very long hitch exists for a few reasons: per-axle weight limit, respecting max weight capacity of smaller bridges, and ease of unloading [3] among them.
Keep in mind that a lot of these traffic devices look way more confusing from above than they actually look while on the ground. From above you can see the whole device at once, and trying to trace a path through it can feel overwhelming, but when you're actually going through it your view is usually restricted in ways that limit your perceived choices at any point in time.
I'd say just the opposite. Indeed, in the UK it's normal for the signs leading up to a roundabout to include an overhead map view, since that's often the easiest way to understand what you need to do to get where you want to.
Agreed. I use to not pay attention to the layout at all. Instead, I resorted to counting down the exits I was moving past them, whilst remembering myself to gradually changing lanes to the left, paying attention to cars on the adjacent lanes. Because of this, I forget to look and plan ahead--almost like tunnel vision. Suffice to say, it was--and still is--stressful, especially at those roundabouts with which I'm not familiar.
Then I started paying attention to the displayed layout. This helped me with the bearings and lane positioning. At least, that's one item off my list when I'm in the roundabout.
The map/diagram helps people not familar, the only really complicated thing is making sure you get in the right lane, and keeping an eye on those around you.
I grew up in this town, and even had to navigate this Magic Roundabout on my driving test. It's not so bad once you understand how it operates, but you have to pay attention.
Ideally the sign would be 1) Rotated so that the driver proceeds from the base towards the top or sides. 2) Clearly depict the LOGICAL layout (bent slightly towards the physical) of what flow patterns _do_ during the roundabout from that input. 3) Also clearly depict which exits go where.
There should really be two signs actually, one before the diagram that lists (locally relevant roads / landmarks) by lane for sorting (if there's more than one lane in).
PS: The route map should also add a YIELD sign in mini next to the entrance with an according broken line. The interior lanes of roundabouts always have priority and all inputs are yield merges in.
Never underestimate how confused people can get with the unfamiliar. I live a couple of blocks from a fairly standard roundabout and see people trying to exit the roundabout through an entrance to the roundabout or try to go clockwise in the roundabout (this is in Canada) several times a year. This happens even though the design of the roundabout, the road markings, and the signage make it perfectly clear how you are supposed to go through it.
Then there is the less obvious stuff that happens multiple times per hour, like entering in the wrong lane given the desired exit (even though it is marked), vehicles inside the roundabout yielding to vehicles entering the roundabout (even though there is signage), or vehicles entering the roundabout failing to yield to vehicles inside of it (same signage).
As for non-standard roundabouts, those can confuse just about anyone since people often don't realize that it is a roundabout.
No discussion about roundabouts can be complete without a mention of the (mostly) Dutch "turbo roundabout", where the lane you take going into a multi-lane roundabout depends on where you want to exit, and you can't / are not allowed to switch lanes while on it:
This is literally just how you're supposed to go round any roundabout. Right lane if you're going straight ahead or right (to any extent), left lane otherwise. Anything else _will_ cause crashes, because vehicles will necessarily have to cut across each other to exit the roundabout.
The "turbo roundabout" might make this explicit, but it's not different.
This is hugely oversimplified and doesn't really correspond to real life. Not all roundabouts are symmetric and not all have four entry-exit pairs. Many roundabouts have two lanes on some entries, but a single lane on others, similarly for exits. In scenarios like this you will inevitably have to switch lanes in some scenarios. It isn't really as big of a problem as you make it sound though, since roundabouts naturally have everyone go slow, crashes are very rare so long as the layout is clear.
> Not all roundabouts are symmetric and not all have four entry-exit pairs.
I didn't say or imply this. The rule works for non-symmetrical roundabouts without issue. To phrase it differently:
If your exit is to the right of a hypothetical line extending across the roundabout in your direction of travel upon entry into the roundabout, go in the right lane. Otherwise, left lane.
> In scenarios like this you will inevitably have to switch lanes in some scenarios.
No roundabout I've ever driven through in the UK has required lane switching, unless I was in the wrong lane to begin with.
A turbo roundabout is directionally biased while "any roundabout" doesn't have to be. A turbo roundabout also does not allow u-turns which becomes quite the limitations for road systems wanting to utilize medians for left turn control.
E.g. a standard 2-lane by 2-lane roundabout intersection may just as well look like this https://i.imgur.com/jqhMxW4.jpeg. Note the entrance markings allowing all lanes to go straight with 1 alternative turn direction per lane choice, the exit markings allowing dual lane exits in all directions, and internal markings allowing u-turns (the roads in this case have medians farther out). It has some of the downsides you mention but also some upsides in exchange for allowing slightly more lane flexibility. Regardless, you're definitely not supposed to follow the turbo's rules in that roundabout.
Now you could "no true Scotsman" it and say all the other roundabout types aren't roundabouts because they are supposed to be like turbo roundabouts to be so... but that still leaves needing the distinction in types, for which everyone calls one a turbo roundabout and other variations different types of roundabout.
It's only the difference between CI enforcing code style vs manual PR reviews that have a checkbox for code style. They accomplish the same, but one is infinitely better.
It seems this would solve the problem with normal roundabouts where you have a lane you should be following but know that a vehicle in an adjacent lane is likely to infringe on yours.
I live near this roundabout and drive through it almost daily.
> Drivers going northbound on SR 203 traffic may need to yield twice – once when entering the roundabout and again if traffic is passing between the two islands. If you think about it, that’s just following the same rules a second time.
The one key difference from the average (American) roundabout is the second yield. After you've waited your turn and entered the roundabout, you're required to yield again within a few feet. Obviously this is not an impossible task, but the signage leading up to the roundabout from northbound SR 203 doesn't at all indicate the shape of the roundabout. The navigation sign at the entrance only shows a single roundabout.
The second yield point is indicated with the standard yield sign and triangle markings on the road. But judging by the amount of detritus scattered on the ground, as well as the recent addition of "YIELD" text painted on the road and orange flags attached to the yield sign (both not present at any other entrance to the roundabout), the yield-twice pattern is not obvious to everyone.
Plus, the topology of the roundabout isn't conducive to seeing this from the ground, either; the relatively sharp right turn leading into the roundabout places the second yield sign out of your forward vision when you're approaching the roundabout, and the whole intersection itself is very slightly tilted away from the northbound entrance, making it really tricky to see and understand it when approaching.
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Anecdotally, almost every time I've driven through here while there is simultaneous traffic from northbound SR 203 and northbound 203rd St. SE, the northbound 203rd St. SE traffic ends up being cut off by drivers failing to yield at the second entrance.
Roundabouts get a lot of praise whenever they're mentioned, and from a traffic flow perspective that's understandable - if by traffic you mean motorised traffic. For pedestrians and cyclists they are worse than the alternative (lights - or even a simple intersection) in my opinion.
Citation needed. As a cyclist I prefer roundabouts: they're faster than lights and don't rob my momentum, and they're safer than uncontrolled intersections/4-way stops because all the cars are coming from the same direction.
Caveat: this is for simple, single-lane roundabouts. Multi-lane roundabouts are gnarly for cars and worse for cyclists.
Apologies. A bit of a blanket statement on my part. There are definitely examples of roundabouts built properly (where cyclists and pedestrians are considered first-class users). Sadly not that common in my experience.
As you can see, they are building a pedestrian overbridge on the north side, but consider what you would have to do to traverse in any other place as a pedestrian (or get across anywhere currently). Here's a suggestion from Google (i.e. just pretend you're a car): https://maps.app.goo.gl/AiBoyWk4Z7bFr21z5
The above is in one of the busiest parts of this city. It's not like there are no people wanting to walk. In fact I found myself in exactly this position here not too long ago. I wanted to get from the mall side to a cafe on the opposite side. I gave up and ate a sad meal in the mall :(
In my experience[1], if there’s no bike path roundabouts are better, in particular for left turns. But on a bike path they are usually not much fun, basically requiring negotiating with drivers 270 degrees apart at the same time.
My preferred roundabout is separate bikepath that joins the road just before and is a part of the same surface, usually found in bike friendly places.
If you are on the bike path it really depends of the configuration and how large they are. Ideally you want te driver to have completed his entry so that he can focus on the bike lane. Best ones are those that have an elevated bike path that is seen as a speedbump for the drivers: they are forced to slow down and look.
I do agree that the roundabout pictured in the article does not seem to include any considerations towards non car traffic, but at least in Germany the vast majority of roundabouts have seperate bicycle lanes and zebra crossings on all entrances, meaning foot and bicycle traffic has right of way. As a pedestrian I vastly prefer these to intersections in nearly every situation.
> For pedestrians and cyclists they are worse than the alternative (lights - or even a simple intersection) in my opinion.
As a cycling Dutch I prefer a roundabout to a traffic light. As a roundabout doesn't force a fullstop and takeoff again.
Also because stopping/get going again is more difficult for elderly/injured people.
I agree they're a pain for pedestrians (cars are faster, drivers too busy looking at every other car entering the intersection to look at pedestrians) the Dutch do car and bike roundabout well (embedding the car one in a bike one)
Elevated pedestrians crossing (which means the crossing is a speed bump for drivers_ is the solution because roundabouts are actually safer than regular intersections once drivers are forced to slow down.
I know all those speed bumps are annoying when you are driving but elevated crossings and bike paths are great traffic calming solution as screaming your engine between speed bumps soon gets very old and tiring and even the most aggressive drivers just end up staying between 12 and 20mph (20-35kph) in the sections that involve pedestrians and cyclists.
The Dutch roundabout design is amazing for cyclists. See here [0] for a more detailed explanation, but the tl;dr is: Second, outer ring that's a bike lane - motorized traffic has to yield so bikes never have to stop and lose momentum.
In Cambridge we have recently had both our first Dutch roundabout and our first few Cyclops [0] junctions and I have to say I actually prefer the cyclops. Yes, you lose momentum if you want to turn and the throughput doesn’t match a roundabout but you can use it as a normal cross roads if you want or use the protected turn with lights around the ring without worrying about whether cars have actually seen you and understood that it’s your right of way. My opinion might change if I lived somewhere where people were used to Dutch roundabouts.
Strong disagree, a well designed roundabout is both safer and faster for both pedestrians and cyclists. See this roundabout [0] from Delft, Netherlands for a good example. Pedestrians have right of way over everyone, then cyclists, and lastly there's a set of traffic lights to give trams and buses right of way when they come by. Cars come last and traffic flows smoothly and safely.
I like the order of priority here. It's as if the designers ranked travellers by the magnitude of their kinetic energy, and forced the highest-energy travellers to exercise most caution. How sensical!
Australian who lived in Washington state for 4.5 years. Very happy to see those kind of changes. Much better and safer than 4-way stop intersections and I hope American drivers will figure out eventually how to use them
Aside from one old lady that I saw doing laps a few years ago after our nearby roundabout first opened, it seems like most people figure it out pretty quickly. But they're too comfortable with it, and most people blast through without even hitting the brakes. That brings its own problems.
I did wonder that. The article says it "slows traffic" but looking at the picture it's basically just lines painted on the ground. Does it really slow anything? A proper roundabout with a fully raised centre not only slows people down but forces you round so any collisions that do happen are minor glancing ones rather than catastrophic perpendicular ones.
Generally, they are designed to naturally make the driver slow a little to see other cars on approach. Often it's paired with slight turns just before the intersection which also does the same thing partly. Some places (most?) actually put obstacles like trees to make it harder to see other cars from further away.
I suppose it depends on what is meant by traffic and I suppose it does depend on whether "slows traffic" means slowing down compared to just zooming past with a green, or drives at a slow speed.
I would think that a) it slows traffic compared with zooming past and b) it's not that slower
On average, I suppose, smoothly moving traffic at slightly slower speeds will be more efficient than 3 lanes of stopped traffic and 1 of fast.
Given the amount of space if I were driving through it I'd wish they had just made it a little larger so it could be a normal "full circle" roundabout. Sometimes the biggest problems with roundabouts is the number of variations. "You can use this lane to go that way here but a mile up if you want to go that way you want to make sure you're in the other lane". Not to mention it seems somewhat easy to speed through without even bothering to slow down for certain entrance/exit pairs.
"Drivers going northbound on SR 203 traffic may need to yield twice – once when entering the roundabout and again if traffic is passing between the two islands. If you think about it, that’s just following the same rules a second time." [my emphasis.]
Firstly, of course, if you are new to it and have not heard about it in advance, you won't have much time to think about it. Secondly, if your mental model of a roundabout is "yield to enter, then you have right of way", this will seem counter-intuitive. I hope they put up a yield sign and corresponding road markings at that point, but the latter are not there in the accompanying aerial photo.
I am also curious as to how navigation systems will tell drivers how to negotiate this roundabout. They have trouble with a somewhat similar roundabout in Kingston NY, at the intersection of Albany ave., Broadway and Colonel Chandler drive.
Update: The accompanying video shows there will be yield lines at the point I am concerned about, but it is also ambiguous about how the rules of the road apply there: "The circulating roadway goes around and between both central islands... Those drivers already in the circulating roadway have the right-of-way."
>The new roundabout needed to be built in the same space as the old intersection. To the east is a steep hill. To the southwest there are protected wetlands. There wasn’t space or budget to mitigate the potential impact in either direction.
I'd like to think I'm clever but I cannot claim to be able to come up with alternative shapes to intersections without first having read the blog post about what they chose :).
Budget to fix the hill yes, it's a real life thing, but one can still wish they had been able to allocate things to do it right. As far as the wetlands... https://i.imgur.com/x0WGHXa.jpeg how many lives is a small part of that narrow strip of wetlands between a farm and 2 roads worth? Easy to change? No... but the right thing to have changed? I think so. Now that they've done neither the intersection is still not very safe (IMO, time will tell) and the limited budget was consumed in doing so.
Solely focused on dealing with "what sounded like the easiest and cheapest intersection to put in" I think they did a decent job, I just wish they had been able to do more. Intersections like this not only remain unsafe but give a bad public taste to roundabouts that are able to be properly done - "Oh I HATE roundabouts, I can't ever tell when to yield or where the lanes go. I don't want one in town" when really it's just a horrific roundabout they went through.
I drive through this roundabout. It’s such a huge improvement. And little confusing at first due to being two roundabouts in one, but not hard to navigate.
US here. There seems to be an obsession at the moment with adding roundabouts in my area. They don’t always fit where they are put. Some of them have a stop sign in the roundabout?
When asked why, the answer is reducing “points of conflict”, which is a static variable. There aren’t actually studies being done before or after to see if makes the flow of traffic better.
They are also adding them in walkable areas with the express intent of “traffic never stopping” which doesn’t go well with pedestrians crossing the street.
I think we can find better ways to spend money… including the salaries of the people dreaming up bizarre applications for these things.
> Some of them have a stop sign in the roundabout?
Traffic gets much heavier and we'll need stop signs at our roundabout near my house. During rush hour it has predominantly one flow of traffic and nobody slows down below 30-35 mph so getting into the roundabout can be difficult. A stop sign would defeat some of the point of a roundabout but it may become necessary to enforce safety.
How big are the roundabouts? I've read one of the problems that can be had is smaller ones, like in this picture, allow drivers to go through at high speed unimpeded. The "ideal" design seems to be to wiggle the road the opposite direction of the turning motion then force going around a decent sized center. In this way going around a roundabout quickly isn't impossible... but going 35 mph would make most feel quite uneasy. The downside is it greatly amplifies one of the biggest roundabout downsides: the amount of space needed.
Seattle Department of Transportation and Washington State DOT have honestly gotten way too creative. It's like every city, every locale, and sometimes every street has a new collection of obstacles and rules to circumnavigate.
Roundabouts are great, but they should probably be round. In this case, it seems that it'd be easy to navigate if the two roads were brought into a single, simple roundabout intersection like you see at any other location.
The article explains why they made the decision not to do a traditional dog-bone interchange with two circular roundabouts. Namely, there were right of way limitations and a need to incorporate heavy farm trucks making a left turn. So, they ended up with basically 1.5 roundabouts which represents a simplification over the dog bone.
The lack of turn signal usage in the region also makes funky roundabouts much harder to navigate. Like you have to wait until there is a large enough gap in the cars to enter the circle, even if none of the cars actually end up intersecting your path.
It is intentional. The idea is to force drivers to reduce speed, and the mechanism is because it isn't familiar to the drivers. The claim is it forces them to be thoughtful.
Whether or not it works or is a good idea is not something on which I'm opining.
It's basically always safer to make a higher speed driver uncomfortable continuing at high speed. Reducing high speed through driver discomfort is 99% of what saves lives in road design.
Neither of these really solve the problem if you're trying to go anywhere other than the first exit. OP is right, this is an issue with roundabouts and you end up needing traffic lights in this case (at least at peak times)
Sometimes tunnels are builds to avoid lights when going straight is the direction favored by the majority but it can force an unwanted loop if you stayed on that lane and you didn't realize in time you had to go right to take the roundabout.
As the credited inventors of the modern roundabout, I've always wondered how the UK traffic planners managed to misunderstand their own creation to the point that they come up with such designs..
An other baffling design I've encountered in the UK is a roundabout with traffic lights half-way through.. Wasn't the concept based on removing traffic lights to fluidify traffic..?
As a whole, if designers come up with far-fetched designs where drivers struggle to understand what's going on, they are doing something very wrong. Assuming the average driver is already barely in control (phone distraction, screaming kids, lack of sleep, medication, subpar vehicle control, etc), the last thing you want to do is remove even more situational awareness by coming up with over-complicated designs that require serious thinking.
The argument that people will slow down because they don't understand what is happening is a fallacious one. Yes, they will slow down, but then, under stress, they will probably default to some instinctive basic reaction which has a high probability of being incorrect, leading to accidents. An illustrative example can be made with traffic videos of American roundabouts.
> An other baffling design I've encountered in the UK is a roundabout with traffic lights half-way through.. Wasn't the concept based on removing traffic lights to fluidify traffic..?
This is indeed a weird one from a US perspective.
The way to think about it is not as a roundabout with traffic lights, but as a light-controlled intersection in the shape of a roundabout.
A roundabout-shaped intersection can handle more variations than a normal intersection, you can have more than 4 roads, or roads entering at odd angles.
As for what the advantage is of having lights on the roundabout as opposed to on the approach, I have no idea.
Roundabouts with traffic lights are a bit of a failure alright - and the larger ones are i'd argue not roundabouts at all - they just share the shape.
I believe traffic lights are always trying to solve a capacity issue - where the roundabout has hit it's maximum capacity and is suffering some throughput issue, which tend to sort of get exponentially worse. With traffic light sequencing, particularily dynamically, there is always a way to even out the flow - prioritize a flow that is backing up undesirable or give a particular entrance fair chance to enter the roundabout.
Though once there are traffic lights on every entrance, plus traffic lights mid roundabout and some/all exits, and explict lane markings and merges I think it's not a roundabout.
Slowing down is important though, as it give drivers time to think and react. Whether they choose to use that time correctly is a problem, but hopefully some or all of the other drivers can use patience and avoid an accident. Where accidents happen, I see it's often from mistakes from two drivers, and it's relatively low speed. Better still, accidents are at shallower angles, so injuries are rare. I've heard an statistic that could well be fake that roundabouts have more accidents, but significantly better outcomes overall.
> Slowing down is important though, as it give drivers time to think and react. Whether they choose to use that time correctly is a problem, but hopefully some or all of the other drivers can use patience and avoid an accident.
I fully agree, and I also think that the "original" roundabout design serves that purpose well, although throughput might different than with dynamic traffic lights.
The point I was trying to make was that slowing down traffic through added complexity could be a dangerous approach to take. It's a switch from a low cognitive load approach by simple design -slow down to a stop/almost stop, look to one side, give way if necessary-, to a slow down of higher cognitive load -slow down, figure out how to navigate a more complex (new) intersection, and maybe remember to give way-. So where in the first approach cognitive load is used to assess how to give way, in the second approach some of that load is used to deal with a more complex/unfamiliar situation. And for some users, I argue, that could already push them more towards accident territory as less cognitive capacity is available to properly assess the traffic situation. Sometimes less is more.
The issue that can happen is when one direction has significantly more flow than the other - in this case you end up needing traffic lights otherwise nobody can ever pull out from the minor direction at rush hour.
The other issue in the UK is massive signalised roundabouts used for junctions where traffic volumes clearly justify a proper grade separated junction like a stack, purely to penny pinch. South Mimms A1M/M25 junction is a good example, or the M2/M25 junction where they eventually had to put in free flowing slips eastbound to northbound because the roundabout was constantly congested.
That's not really a problem with roundabouts per se though, it's just bad design choosing an inappropriate junction design purely to avoid having to pay for bridges
Traffic lights are sort of a 'patch' on them. They usually start off without them, they realise theres flow issues that prevent people coming out of one junction, and its going to either be too costly or impractical (space is a massive issue in the uk remember) to switch to something more complex, so lights are used as a permanent stopgap.
One example of where this has been an ongoing issue for decades is the Black Cat Roundabout on the A1 (https://en.wikipedia.org/wiki/Black_Cat_Roundabout). It's gone through numerous changes to improve things, with lights at various points being one of them. Finally now though its being completely redeveloped to a grade-separated junction as traffic has massively outgrown the roundabout.
It may be unusual there, but in the UK we have loads. Some are smaller than this: the minimum roundabout is just a paint circle. They aren't a problem
Most people here actually prefer roundabouts to traffic lights because you keep moving (although this is partly selection bias- traffic lights are deployed at junctions where a roundabout would fail to evenly arbitrate the different flows )
That one is a bit odd, because the central bit looks like a roundabout but is not. To navigate it you need to forget the central bit and focus on the five mini roundabouts
You may feel less enthusiastic about it once you watch the linked video. I wouldn’t exactly call it a roundabout. That’s only what’s at the center of it.
Ok fair enough, that extra bit does make it slightly more complicated. Having said that though, I would not be fazed by this, and I don't think many UK drivers would be - because we already deal with many that have more parts. When I was learning to drive, I found a particular triple roundabout quite painful but no longer have any difficulty.
There are two skills you need to pick up to deal with any roundabout system. The first is judgement of how distant other vehicles need to be before you can enter. As a learner I used to irritate the drivers behind me by being far too cautious; on a busy roundabout you can't expect an enormous gap, so you need to know what length of gap the other drivers will expect you to take advantage of. This you can only learn from experience.
The other is to plan your route, because you need to choose your entry lane based on where you want to go. These days your navigation app will probably tell you the best entry lane.
Whats not mentioned in the article is that this particular intersection has a
(15mph residential access road - top right)
(25 mph farmland road - bottom)
(50mph country highway - left and right)
Previously, only drivers from the 15mph and 25mph roads had to stop!
Visibility coming from the south would also be terrible to check for incoming highway drivers (left is blocked by foliage, right the road curves out of sight), so getting the highway drivers to slow down is a welcome improvement here.
There is also not enough space to add at the intersection here either, its seemingly bordered entirely by private land.
> Previously, only drivers from the 15mph and 25mph roads had to stop!
This is something which drives me crazy with a decent number of roundabouts that the Wisconsin DOT constructs. You have a rural intersection where a local road crosses a major highway, and the local road has a stop sign in either direction. Then the DOT slaps a roundabout in there, greatly inhibiting the highway traffic which is 95% of the traffic going through that intersection. That is not a good use case for a roundabout! But for some reason they insist on doing them anyway. It's terrible road design.
The area borders wetlands and a very steep hillside where one of the roads intersects. And the regular flow of traffic pre-roundabout was more like 60-65 mph.
I'm not arguing about whether the roundabout was the correct choice. However, the department of transportation can eminent domain whatever they want. And neither hillsides nor wetlands are insurmountable for modern civil engineering.
Roundabouts always make think about the two parts of problem optimization, determining your objective function then optimizing. Many classical failure states for real world problems seem to involve having an OF that is incorrect then prematurely optimizing. Think of the rich guy who wants “love at all costs” and then pursues women with expensive gifts and fancy restaurants. You may achieve your aim but perhaps you won’t get what you want.
I think the same is true of roundabouts. One part of the experience that seems almost never to be mentioned is the experience for a passenger when encountering a series of roundabouts. Let’s say you had some bad oysters and are resting your head in the back of the car on a pillow and praying you can make it home before you upchuck your dinner. Perhaps some road engineer decided to put 5 or so roundabouts consecutively to “optimize traffic flow” then somewhere around spin number 3 you lose your stomach on the backseat. Perhaps the trip was not “optimal” for you.
We have a few roundabouts where I live in the USA now, and they are absolutely wonderful, apart from the occasional clueless driver who doesn’t know how to use them, which seem to come in two varieties: 1) blast right into them without yielding or even slowing, or 2) Going the wrong way. In their defense, they probably have never seen them or never learned about them in driving school.
A roundabout looks to be more appropriate here compared to the previous junction. The only thing that catches my eye as a UK-driver is the road markings would go against the way we would mark roundabouts in the UK. The dashed lines should indicate where the priority is - and that is on the roundabout, so in the UK there would be lines going across the road as you approach the roundabout, indicating that you are a minor road connected to a major road which has priority.
Driving in Morocco is a very special experience. Some roundabouts follow the 'priority on the right', which is a default if the junction doesn't indicate priority, in much of Europe (especially France). This means you give way to those approaching the roundabout, as they are on your right. But there are also roundabouts where you have priority on the roundabout. The only way to tell are to look at the road markings which help to indicate the priority.
Roundabouts are a nuisance, while they offer some merits, the sheer lack of education around how to navigate one makes for a very unpleasant experience in most cases.
That's how we felt too until a couple years passed and we no longer noticed it. Now that people have learned how it works its much faster than the old stoplight stopsign combo
Wait, what is the nuisance-- the roundabout of the lack of education? What happens if we replace "roundabout" with "stop sign" in your statement and assume a population that was never trained on what "stop sign" means? Would that work better?
"We don't have experience with a new better system so we must never adopt it."
And so the lack of experience continues on forever.
Come on, man, people will figure it out.
There will always be the dashcam vid of the yokel who tries to make a left into one despite the obvious signage and directional nudges, but dashcam youtube has shown us there's always people out there who have no common sense and should not have a license. Just pop some popcorn and continue scrolling.
Yes, it's a few miles outside of the nearest town. It's the intersection of a state highway and some small roads that mostly lead to farmland. Not much pedestrian traffic expected there.
is it even a roundabout or just a strange 3 way intersection?
like in a normal roundabout you always yield to the people in the roundabout basically assuring things won't get "stuck" if one road has much more traffic then another
but on the picture it looks (through the lines) as if the people in roundabout have to yield
in which case it wouldn't technically be a roundabout but just a 3 way intersection which separated and lanes to archive some traffic flow optimizations and calming as necessary (as such the sharp edges might angels might be very much intentional)
and I agree it looks confusing but it also looks like it will slow down traffic in all but one of the directions
EDIT: Photos on google maps have much more sane lane markings and it resolves the question if you have to yield when entering it (yes you have). It generally looks much less confusing there.
My my local pet peeve of horrible roundabouts, you got cycling paths, a tram line, a bus line with different exit and cars. (the hexagonal cycling path with internal car circle causes the cars to not see a lot of the cycling paths making accidents frequent): https://www.openstreetmap.org/#map=19/51.996997/4.354979
One area where a 4-way stop sign intersection is somewhat superior to a roundabout is the notion of taking turns -- in the States it seems like busy roundabouts are an opportunity for one stream of traffic to just plow through, completely ignoring everyone else who also has something better to do than sit around waiting for others to be courteous :)
I like to hear from the actual traffic planners. Enough laymen rant about why roads are made the way they are, but there are usually considerations they don't know. I'm very curious what kinds of systems get used for planning and what data they have.
I fail to see how this helps over more traditional designs. Not to mention tight roundabouts always have horrible curbs that trucks have to smash into to try and jump over to make the turns, and they are never gentle bumps, they are always tire and curb damaging trash, especially for heavy loads which are primarily the vehicles that need to jump the curbs.
All the roundabouts around me I wish they would just get rid of, I can navigate them just fine, but they are way too small, over congested, and dangerous because the 5 seconds you have to read the signs as you approach to know whats going on is too much for anyone non-local which makes them unpredictable and nervous drivers.
Gravel trucks are the last trucks that should ever be hopping curbs though, even gentle ones. Gravel trucks already require many roads to be upgraded due to the weight and damage they do just to a flat surface. A truck carrying diapers and crackers won't mind so much, but when you got 50 tons of gravel then even a small 1 inch jump causes significant extra forces on both the road and the truck.
That road has been carrying gravel trucks for decades. The smart WSDOT engineers took into account the business with large trucks that is just a mile away when building this roundabout.
OTOH if you can't read the sign where to turn right, you can keep turning left, make a full circle, and check the signs again, and again if needed, in under half a minute. All without creating a problem to anyone around you, and being safe yourself.
I'll take it any time over a typical highway exit; if you miss it, or uf you take a wrong one, it's usually dozens of miles before you have a chance to take any corrective action at all.
> Not to mention tight roundabouts always have horrible curbs that trucks have to smash into to try and jump over to make the turns, and they are never gentle bumps, they are always tire and curb damaging trash, especially for heavy loads which are primarily the vehicles that need to jump the curbs.
I'm not a fan of roundabouts, but the recent WSDOT roundabouts I'm subjected to have gentle curbs, at least for now, so that part isn't so bad. The part where I actually need to look left and right simultaneously to see if there's room for me to join the flow, and also watch for pedestrians (if present) isn't so great.
And I'm really not a fan of the unbounded wait when there is a large flow that crosses my entrance, which could result in a very long wait when the large flow comes from rush hour conditions or a ferry offloading.
For one, roundabouts turn what would be a T-Bone intersection into a glancing hit. I think that's the biggest safety benefit. They also improve the flow of traffic since there's no starting and stopping (think of it like a stoplight is a mutex lock and a roundabout is a spinlock).
And because they have no electronic or moving parts, the upkeep is minimal. There is some cost to a traffic light, particularly as you start adding weird phases and whatnot.
Depends where and who you're talking to. Overall though, I'd say it's probably most often roundabout, traffic circle, and rotary (in that order) and I haven't heard much else. And yes, they are different things to traffic nerds, but I mean places (particularly in the NE like Massachusetts) just call them all rotaries regardless what the traffic department teaches https://www.mass.gov/info-details/what-are-roundabouts.
Of course this could just be banter, in which case: absolutely not, we tout our motors through circular-wirculators just like anybody else!
In NJ we have traffic circles which are larger, much higher speed, and consequentially much more dangerous. They have been re-engineering them in recent years to be more like roundabouts but it used to be you could slam around one of them doing 55mph or so without stopping or slowing much to enter (until it backed up).
At least that one is small. They'd know for sure from the change in numbers pretty soon if it improved things or not.
But for multi-lane ones I absolutely lose my shit and freak out when I get into one. Many decades of driving experience, but when in Europe (France, Italy, Spain) i encounter a multi-lane roundabout, every time it feels extremely confusing and unpredictable. People moving in all directions, cars, scooters, you need to calculate which lane you need to get into, and get out of, and do all that while accommodating crisscrossing neighboring vehicles who are all also trying to maneuver in every direction. Having to turn the entire time makes it feel very fast and dangerous, always paranoid about crushing some scooter that I didn't spot from one of the many angles while turning. Doesn't seem to get easier with time for me either, unlike all other driving. Glad we don't have multi-lane roundabouts in CA.
One of the first things I did after getting my driving license was fly to Lisbon and rent a car there. At the time, you left the airport by merging onto a four lane roundabout with essentially no lane markings with people driving like maniacs and 5 or so exits for different highway directions. At the end of that vacation, I was driving a lot more confidently. But I wouldn't recommend that Darwinist approach to learning how to drive in the real world.
When done properly, multi lane roundabouts can be quite efficient. They are common in Europe as an alternative to just having a lot of traffic lights at any junction. Some of the bigger ones can also have traffic lights.
A good guideline is that if you need to go 3 quarters around, you probably want to be in the left most lane when you enter and move right as you progress. In case of doubt, just go around a second time. If you are too far right, merging left is something you want to be careful with and not necessarily legal in some places. But it's not that different from sorting into the wrong lane for a crossing. You kind of commit to where you exit before you enter. Usually the signage should help.
The most annoying thing about roundabouts is the navigation endlessly going "At the roundabout take the second exit" (i.e. go straight on), which gets really annoying if you are on the ring road of some city that has roundabouts every few hundred meters. Which accurately describes a lot of smaller cities across Europe these days. Safe and efficient. But also tedious. If in the Netherlands, beware of your right hand dead angle and be on the lookout for scooters, e-bikes, etc. when you exit a roundabout. You are supposed to yield to them and they can really come out of nowhere.
IME (also observing other drivers), the usual multi-lane roundabouts are something you get comfortable with after just a little spaced repetition and then it's not all bad.
There are major cities in those countries with a few exceptionally gnarly ones, though. I don't blame if you're traumatized if you ever found yourself circling Arc de Triomphe in Paris, for example.
The comment section on the youtube video is soo good. Everyone seem to almost have accidents and everyone complaining. Think prob they need to work a bit on this design.
Roundabouts are hostile to pedestrians. At a 4-way stop, cars actually stop, and they are forced to pay attention. A roundabout is just a vortex of confused drivers who are paying as much attention to what's behind and to the side as they are to what's in front of them. Much better would be to expand the roundabout and straighten its sides until it's a square block with one-way streets -- and so, no longer a roundabout.
The centers of roundabouts are typically overgrown wastes of scraggly grass mixed with litter. Each a tiny sacrifice zone. They remain that way because nobody goes there on foot. We just see the mess from our cars.
A roundabout takes what could have been a village green and turns it into something just barely less terrible than a highway cloverleaf.
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So I actually read the article and am not really proven wrong. They do this insipid
> Making a roundabout for everyone
thing, like laying pavement is the Civil Rights Movement, but "everyone" seems to only mean "vehicles", a word I see several times, together with "drive", but never "walk". I see no crosswalks, no pedestrian flashers, and no bike lanes. And the center island has been designed so larger vehicles can drive over it; I understand their reasons, but that also means it provides less protection to anyone seeking refuge there as they try to get across.
Sometimes traffic isn't a problem to be solved. It's the universe telling you that there are already too many cars.
Where I grew up in a rural part of the US, we had one terrible 4-way intersection between two undevided highways. Over time they added lights, then experimented with different signaling systems, but every day it would back up for several miles in a couple directions, and add up to 30 minutes to some commutes. Then there were the inevitable accidents as people tried to rush it, making things worse all around.
They replaced it with a roundabout about a decade ago, the population in the area also has increased dramatically in those years as farms turned into suburbs, but the backup is entirely gone. Theres no need any longer to maintain lights and switching systems, and the accidents are almost nil. Nobody has died there in years. People complained at first because it was "weird" then they realized they were complaining at home a half hour ealier than they would have been, so they stopped.
They've since added a few more in the area and have even gotten very experimental with a double diamond interchange that's also done a lot of good. There's something in the water at the planners office. Seeing that transformation though and the immediate benefits has turned me into a lifetime fan of the roundabout.