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Comment by smeej | Hacker News Reader

I think you're right about single vs. 2+ lanes. It doesn't matter how many diagram signs they put up before the roundabout entry, people will NOT understand a roundabout with more than one lane, and under no circumstance will people going straight through realize they have to yield to someone coming from the opposite side who's going 270° around the circle and exiting from the inner lane.

Roundabouts are fine if the rule is, "Just get in there without hitting anybody and go around until you're ready to leave," but expecting anything more than that from most drivers is a lost cause.

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> people will NOT understand a roundabout with more than one lane

We have tons of 2-lane ones and everyone understands them…

Where are you? We have tons of 2-lane roundabouts in Sweden as well, and I can assure you that far from everyone understands them. And even if they understand them in the sense that they got the theory question about them correct on their driving test, everybody certainly doesn't implement that knowledge consistently and correctly when faced with a 2-lane roundabout.

Bratislava, Slovakia. I don’t recall anyone I know having an accident on a roundabout.

Newbie drivers I talk to/drive with are much more worried/unsure about crossings (both the ones without traffic lights and the big ones with many lanes) and of course about parking.

Of course, there will be SOME people who are clueless on roundabouts, similar to how there are always some people who will stop on a highway after missing an exit and pull back. But let's not argue about the long tails.

IMO if you learn to drive at a time when roundabouts are already ubiquitous, they are trivial. At least I found other aspects of driving more difficult.

> there are always some people who will stop on a highway after missing an exit and pull back.

What?? People do that??

My mind is blown. I've never once seen that happen, so the possibility never entered my mind. Now that I think about it, though, I should probably be more surprised that I haven't encountered it.

Some people drive crazy

https://youtu.be/r86kxxU-LUY

Traffic police here in Romania had to actually add some stuff to the legislation that would make 2-lane plus roundabout traffic easier to understand, the reason being that the traffic policemen themselves had conflicting opinions about who had the right of way inside said roundabouts (when changing lanes, for example).

Our town has loads of them too, and everyone think they understand them. Still accidents are common because people think it's ok to just go straight through by changing lane to inner and then directly exiting without yielding to the ones crossing their path in the outer lane.

At least in the Netherlands its recommended that the two lane roundabouts have mountable curbs specifically to prevent lane changing.

The US is unfortunately loth to install any sort of divider more than paint or a feeble plastic post, and less than a jersey barrier.

We have quite a few without curbs too, but they usually have markings for what lane is for what direction and are "skewed" so that you don't normally have to change lanes.

Example: https://maps.app.goo.gl/3z6NZXGdb2HRVtfW7

In my country accidents per roundabout are far less common than accidents per traditional crossroad.

Sorry, didn't write the whole thing. Yes, it's much less accidents and those that happen are at much lower speeds and leads to less bad accidents.

There's lots of multi-lane roundabouts in the UK, and generally seem to work well, but they're often inconsistent with how lanes merge or depart.

One that gets me every time I go past is one where there's like 20 signs saying that both lanes continue to the main road to the right (270 degrees around, the UK so driving on the left), but I don't think I've ever been through there and not have someone try to merge in to me trying to get into the left lane to exit, despite both lanes leading to that exit.

I agree, Australian cities seem to think that they solve every traffic issue. There is a double lane less than 200m from my house.

The shitty part about roundabouts is when people allow blocking of the view to the right on the round about so you are unable to see incoming traffic till its almost on the round about.

The number of drivers who think you can freely exit from the inner lane suggests otherwise.

Not sure exactly what you mean by freely, but in most popular roundabout designs you can exit from the inner lane. A "standard" two lane roundabout will have two lanes entering AND exiting. You never change lanes in roundabouts, at least where I'm from. Only in a massive multi-lane roundabout (that's at that point more like a ring road) would you ever change lanes to exit.

e.g. for a standard two lane roundabout with four exits, if you enter in the left lane, you can exit directly out of the 2nd, 3rd, and 4th (i.e u-turn) exits, but always in the left lane of the exit. If you enter in the right lane, you can exit out of the 1st or 2nd exits, but always in the right lane of the exits. With this design cars travelling alongside you can never cross your path, only cars entering the roundabout ahead of you can cross your path and it's their responsibility to yield.

The thing that most often causes problems is people in the outer lane NOT exiting (e.g. thinking they can take the third exit from the right lane) and swiping the car in the inner lane correctly taking the second exit.

The car from the inner lane swiping into the car in the outer lane is the exact issue I'm talking about. The problem is when drivers enter in the left/inner lane, fully intending to take the first exit. If they proceed to exit directly from the inner lane, without first changing lanes, signalling, or yielding to outer traffic, they would intersect with a car in the outer lane innocently heading to the second exit.

In practice, people are not able to navigate two-lane roundabouts in a compliant and safe manner. Any intersection of roads busy enough to have two lanes in each direction is too busy for a roundabout to be safe.

It’s still safer than a normal intersection. Roundabouts prevent HIGH SPEED t-bone and head-on collisions. The difference in safety is easily worth the “cognitive load” of a 2-lane roundabout.

I think drivers will get used to them and in practice there will be few collisions.

> I think drivers will get used to them and in practice there will be few collisions.

I think drivers will avoid them at all costs since even low speed collisions can cause extremely expensive repairs (and even total an older vehicle) meaning they'll never get the practice they need to navigate them safely, yet eventually those drivers will find themselves in a situation where a roundabout can't be avoided and suddenly it's chaos for every car in the intersection.

Even if multi-lane roundabouts were suddenly everywhere we'd probably need generations of new drivers trained to use them in drivers ed classes as teens before you could just trust people to be able to navigate them correctly

> The problem is when drivers enter in the left/inner lane, fully intending to take the first exit. If they proceed to exit directly from the inner lane, without first changing lanes, signalling, or yielding to outer traffic

Yes, in that case a driver not understanding the rules of the road (that you can't take the first exit from the inner lane, which is usually clearly signed) could cause an accident. The exact same way turning right from the left lane in a signalized intersection can cause an accident. The question is, what's the damage of an ignorant driver and how fast do people learn? The research indicates that right-of-way incursions in a roundabout result in dramatically fewer injuries than right-of-way incursions at other types of intersections, and the research also indicates that contrary to your belief, drivers actually do learn how to use them.

The experience of most NZ cities and towns on a daily basis says otherwise.

They are right to. Simplified greatly, the further in the roundabout you are, the right of way is yours.

The exception is you can obviously not shoot straight from the left lane to the first exit.

In a 2 lane roundabout it is very simple. Enter in the left lane and you can exit 2nd or 3d, enter in the right lane and you can exit 1st or 2nd.

Where it gets complicated is roundabouts with 2 lane entry but only 1 lane in the third exit. Then you have to change lane right halfway through and be careful with people entering prematurely from your 1st exit, or people incorrectly staying in the right lane past the 2nd exit. It’s not always obvious but for those entering the rule is the same, since they enter after you, they should yield to you.

I guess this is depending on country. In Sweden you are allowed to exit from the inner lane. But you have to yield to traffic in the outer lane because you are doing a lane change even if you go straight for the inner exit in a two lane exit. The outer lane is not causing the accident, they do not have to yield and they are allowed to go to the third, fourth or fifth exit fully in the outer lane if they want to. You just have to make sure you don't hit them on the way out.

This however does not stop accidents to happen all the time in this situation because of drivers trying to get past the traffic jam by going inner lane in high speed and then exit in front of traffic trying to get to next exit. And mostly without blinking at all.

Honestly, even looking at a picture showing how a 2-lane roundabout works (https://www.epermittest.com/drivers-education/roundabouts), I still can't understand how it works. Assuming 0 is the bottom and 90 is the right, how is it that a person following the inside route from 0 (exiting the left lane at 180) isn't going to get hit by someone following the outside route from 90 (exiting the right lane at 270)? I would almost certainly use it wrong and/or expect to get hit.

The part you're missing is you have to yield when changing lanes, just like in any other road. If you are in the inner lane and you want to exit, you have to make sure the coast is clear. In other words, you are responsible for not getting hit. If you just blindly change lanes you might get crashed into and that would be your fault.

> The part you're missing is you have to yield when changing lanes, just like in any other road.

This is not true with most roundabouts in North America at least. If you look at the diagram GP posted, you do not change to the outer lane to exit. You exit directly from the inner lane. In fact, you NEVER change lanes in a roundabout. The reason this works (where the inside lane crosses the outside) is because the roundabout is small enough that the traffic in the outside lane has to let you exit as part of yielding to enter the roundabout in the first place. After that, as long as everyone respects which exits they're allowed to take from which lane, there is no more crossing traffic. In practice, if you are in an inside lane, you want to keep an eye on the outer lanes to make sure someone isn't trying to take a later exit than they are allowed.

From GP link:

> Do not change lanes in a roundabout

> Do not travel in the outside lane further than allowed as it may create a hazard for the vehicle exiting the roundabout from the inside lane

That doesn't work. If I enter a 4-way roundabout going left, I will start off in the left lane. I will pass two exits and leave through the third. When I exit, someone from the second exit could be in the lane next to me, going to the road I came from. I have to yield.

When you exit from the inner lane you necessarily have to change lanes because the inner lane is completely inside the outer lane. You may not think of it as a lane change because you're going across the lane not merging into it, but it is a lane change and you have to pay attention.

> I will pass two exits and leave through the third. When I exit, someone from the second exit could be in the lane next to me, going to the road I came from. I have to yield.

No, they have to yield to YOU because you're already in the roundabout. It's hard to believe, but trust me, this is just how it works and all of the links I've posted agree. The reason why it works is because when you're in the situation you describe, for the person entering at the second exit to be a factor, they would have to be entering as you're already alongside the second exit and in the process of exiting at the third. So they need to be yielding to you as they will be crossing your lane. Part of waiting for the gap is waiting for the exiting traffic to clear. Not for only YOUR lane to be empty.

I can't see any links you've posted that agree with what you're saying. I only checked a couple, you said all of them so I figure thats good enough.

Apologies, I mistook some of the ones I responded to with being ones I posted.

Here's a video from Minnesota timestamped to them talking about exactly this scenario in detail. Namely, yielding to all lanes of cross traffic: https://youtu.be/CEhNboz5GPk?si=LxdVQZx0MHrYhl8w&t=196

> With multi-lane roundabouts, it is important to stop for vehicles in all lanes of traffic. Wait until there is a gap in all lanes of traffic and then enter slowly. Never try to enter alongside cross traffic or assume any driver's intended path. One of of the most common mistakes people make when entering a roundabout is failing to yield to all lanes of traffic. Yield doesn't mean just slow down or merge. Yield means that you must wait until all traffic in the roundabout has cleared before proceeding. Make sure that no one is in either lane of the roundabout and then proceed.

The video also has a good overhead view that is better than most at showing the scale of the roundabout. The important thing to note here is that to enter the roundabout, you have to cross the lanes that are exiting, not merge into them. So you are yielding to all exiting lanes.

> Assuming 0 is the bottom and 90 is the right, how is it that a person following the inside route from 0 (exiting the left lane at 180) isn't going to get hit by someone following the outside route from 90 (exiting the right lane at 270)?

The person following the outside route from 90 must yield before even entering. It's very confusing until you're actually in them, but they're small enough that what you're saying usually isn't really a problem (at least in well designed roundabouts). When the car at 90 enters the roundabout intending to take the 270 exit, they yield to traffic in ALL lanes that might be exiting. Not just traffic in the outer lane. If they were intending to take the 180 exit, they only need to worry about traffic in the outer lane (or people incorrectly changing lanes when exiting).

The "correct" answer is the 0->180 car has no indicator on as it enters the roundabout, and has its right indicator on as it exits the roundabout.

The 90->270 car sees the right indicator and lets the other car passed.

The real answer is somewhere between the above and the 90->270 car waiting to enter the roundabout because it is not sure if the other car is actually going 0->180 or 0->270 because they are a shit diver that doesn't indicate on roundabouts.

well, that breaks all schemes, as my experience in 52 years is, that most people don't or won't operate their indicator signals properly. They seem to believe they are for special holidays, or for a particular audience they have spotted (spoiler alert: they are for the opposite). Or, my favorite: Activating the indicator two thirds of the way through the already completed turn, presumably to celebrate the success.

> expecting anything more than that from most drivers is a lost cause

I can't speak to the area you live, but where I'm from we get along just fine. Yes sometimes you still get the odd unfamiliar driver that doesn't understand them, but for locals there's a critical mass where roundabouts stop being avoidable and you adjust.

Are you from Stockholm?

I don't know what the letter of the law is but I (and most people I've seen here in Australia based on driving patterns) interpret yielding to cars on the roundabout as giving way if I will get in the way. If they're still on the other side of the island, and we can both pass through without getting in each others' way, it's fine.

Of course the de facto standard here (which many people actually think is the law) would be "give way to the right" (i.e. left for US) meaning some people will proceed without stopping even if the car to their direct left got there just before them. I think this is predictable since more risk falls on the driver who is going to get T-boned in their driver side door if they don't stop so they will be naturally cautious.

The big issue is that multi lane roundabout forces the driver to watch too many things at the same time while giving him very small margin of error. If you are not fast with reactions and aggressive enough, you can end sort of trapped in the inner lane and people are afraid to do one more unnecessary round.

And that means everyone has to watch both left and right at the same time while also trying to figure out layout (Will the outer lane force me out when I do not what to? Some roundabouts are like that. Will the inner lane keep me trapped? etc)

> It doesn't matter how many diagram signs they put up before the roundabout entry

It doesn't help that often those signs are pretty confusing all by themselves (at least the ones I've seen), and can't really be grokked from a brief glance driving by.

It would be better if all such roundabouts were consistent in how you should navigate them, but that isn't the case in my area.

This. My community built training facilities. Didn't help much. Also, for new drivers these just induce anxiety and give them new opportunities to halt traffic and get horns blasted at them.

Where I’m from, every driver knows how to use these and use them safely.

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