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Comment by maest | Hacker News Reader

I'm all for hating bad infrastructure, but this roundabout seems pretty straightforward? Maybe it's different when you're actually driving on it, but from a topdown view it's clear it's a central roundabout with some extra sidelanes to avoid the roundabout if you're immediately turning right.

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Talking to my American colleagues, they're often perplexed by roundabouts and don't really understand how they fundamentally work. They're also incredibly stubborn when it comes to convincing them that it helps with traffic flow immensely versus a 4 way stop sign.

When you’re walking the stop sign stops traffic for you so it’s a lot nicer. I’ve found that even with a marked crosswalk people ignore you if they’re not forced to stop.

I guess jaywalking stuff makes this harder? Because in the UK for example, roundabouts will often be surrounded by marked areas for pedestrians to cross, but they are not proper crossings. You don't have to wait or expect traffic to stop for you, you just walk across when it's clear.

I don't understand your comment.

* Jaywalking makes.. what harder?

* In the UK, roundabouts are marked with areas for pedestrians to cross but they are not crossings? What are they, then?

* You don't have to wait

* But also you can't expect traffic to stop for you

* What do you do if it does not become clear?

> Jaywalking makes.. what harder?

Crossing the road without a crossing or light or whatever explicitly telling you that you can do it.

> In the UK, roundabouts are marked with areas for pedestrians to cross but they are not crossings? What are they, then?

They are indented areas where the road (and often the centre barrier just before the roundabout) is marked for pedestrians but traffic is not obligated to stop. You cross the road when it is safe

> What do you do if it does not become clear?

If it was such total gridlock you can just cross in between traffic that is not moving?

It's much better when there's no traffic. When there's traffic, it often doesn't stop for you when it exits the roundabout (even if it technically should) because everyone is busy going around the circle as fast as possible (and driving in a circle means they might not have been looking at where you crossed). Sometimes they move the pedestrian crossings way back to give people more of a chance to stop, but that still requires drivers to stop when they don't feel forced to.

And as a pedestrian, drivers going around a circle aren't necessarily going to see you until they're already exiting, even if the city didn't put something large in the center that entirely blocks their vision. Plus, you lose the ability to know which way a car is likely to go until it's already too late.

When I lived in Nashville, I spent a lot of time near a roundabout, and even after they redid it to be a bit better I still had to avoid it for my own safety. The light-controlled intersection next to it was much less of a problem.

The rule in Australia for roundabouts is that you give way to anyone already on a roundabout.

From an advanced driving course I got to do years ago (for free), I learnt that the pedestrian island counts as part of the roundabout, so a pedestrian crossing or on the island should be given way to finish crossing when entering the roundabout [1].

Doesn't always happen in reality.

There is also this idea in Australia that you always give right of way to cars entering on your right (left for US) which is not an actual rule; as in if you are waiting at the line you count as being on the roundabout.

Unfortunately, you will often see cars on the major road blast through a small roundabout with no regard to anyone waiting to enter from the lesser road, making entering the roundabout from that side a stop rather than an equal give way.

[1] Edited for clarity

I almost like them, but my commute long ago involved one that revealed a frustrating pathological case. Constant traffic flow in one direction can make an entrance entirely unusable. It makes the average trip more efficient, but the worst case becomes dramatically worse.

>Constant traffic flow in one direction can make an entrance entirely unusable.

Seems like a poorly designed roundabout then. You should just pull into the roundabout, right after the car already in the roundabout passes by. Something is wrong if one direction of traffic can block the flow from other directions.

> You should just pull into the roundabout, right after the car already in the roundabout passes by.

At the risk of pointing out the obvious: the issue is that there's another car right there, when traffic is heavy.

It's more a poor place for a roundabout. It was a very busy intersection in one direction, where the switch to roundabouts meant there was no longer a break in traffic. What it needed was a light with a sensor to let the very sporadic side traffic through (technically, a roundabout can have this, but the 3/4-way intersection that's always green except when someone needs it to not be is better), what we got was an endless stream of cars blocking the way for a lot of the day. If you pull in after the car already in the roundabout passes by, you get hit by the next one.

>If you pull in after the car already in the roundabout passes by, you get hit by the next one.

Yes, that seems like a roundabout design defect. Seems like the radius of the circle is too large, so cars aren't slowing down enough.

How large is too large?

I'm American with a roundabout very close to my house. The inner radius is 10 meters with an island in the middle, and single lanes in all directions. I have witnessed it successfully navigated at well over 100 kph.

Also, it's not a speed thing. I've seen this at another roundabout near my house. There's a school dropoff near it, so in the morning traffic backs up through the roundabout onto one of the entrances. The rules are that traffic in the roundabout has the right of way, so nobody lets anyone from one of the side streets in.

I guess I'm not a traffic engineer. And there are of course humans-doing-crazy things. But the roundabouts in my neck of the woods are a lot more reasonable. Sure, there is the occasional timid driver who can temporarily gum up the work. I can't say I know if it is the drivers or the roundabout design, or what that would make roundabouts useful in some areas and less useful in others. I bet it would make a good YouTube video if someone were to critique one of the unsuccessful roundabouts (or at least I'd give it a click). And if someone is looking for YouTube video opportunities, it would also be interesting to see how Tesla FSD handles this. Line up 10 or 15 going in one direction, and another 1 or 2 in the perpendicular direction.

I’m typing this just down the road from this Kirkland roundabout. It is fine. I’m used to roundabouts from my old country tho. I do fear someone else will just hit me down there cause I don’t trust people around here on roundabouts.

A breath of fresh air is how much faster getting off I-405 is now. I used to wait a lot on the traffic lights that were there before, and now it is like a mini slow rollercoaster.

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