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Comment by com2kid

6 hours ago

They exist so people cannot run through the stop sign. Their only connection to a round about is the shape.

It's more complex than that. I live in Seattle near a street that has these traffic circles. The design is:

* There is a round obstruction in the middle of the intersection like a roundabout.

* The street going north-south through the intersection does not have a stop sign.

* The street going east-west has stop signs on both sides.

* But the north-south street which doesn't have to stop also has speed humps on it to slow drivers down.

On its face, this seems like a totally bananas design. The street that should be efficient by not having to stop has traffic calming speed humps on it anyway, negating the efficiency. The cross streets get none of the efficiency of a roundabout because they have to stop anyway. And the combination of roundabout and stop signs is very confusing to drivers.

It makes no sense... if you assume the intersection is designed entirely for cars.

But it isn't, it's a "neighborhood greenway"[1]. The north-south street is designed to improve bicycle traffic. The speed humps don't slow cyclists down. The roundabout middle and stop signs on the cross streets make it safer for cyclists to cruise through the intersection without stopping.

If you ever bike commute, you quickly learn how lethal a lot of stopping and going is for cycling. The effort and efficiency really only make sense if you can go a fairly steady speed for much of your commute. Accelerating a bike is a lot of work.

Once you factor in bikes, the design of these intersections makes more sense. At least in theory. In practice, though people are consistently confused by "roundabout + stop signs" and I see drivers blow through those stop signs more than I've ever seen any other traffic violation by a large margin. Because of that, cyclists and drivers going north-south still have to be paranoid going into the intersection. Even though they have the right of way, there's about a 25% chance the other driver won't stop anyway.

It was a good idea, and maybe the execution will work out once people get more educated. But right now it's a mess. I walk along that street often and I spend a lot of time gesticulating wildly at drivers when they blow through those stop signs.

[1]: https://www.seattle.gov/transportation/projects-and-programs...

  • I live by a bunch of these, but worse IMO is the "four way intersection with no signs or circle or anything" where you just kind of hope no one comes fast and hits you (I imagine on a bike where you wouldn't stop if there was a sign this is even more dangerous). Seattle is weird. Traffic circle with stop signs is fine by me, they don't really function well as roundabouts for most cars, anyways, some of them are too cramped to actually go all the way around smoothly.

  • Seems reasonable. Of course there are really good (true) roundabout designs that are great of cycling (and walking), but without understanding the space it's hard to know if they would fit / work well.

    • What they're talking about is basically a small concrete circle (sometimes it's not a circle, but a round-ish shape vaguely near the center) plopped down in a standard residential intersection (sometimes with a lot of stuff in it that blocks the view in case you were worried about knowing if someone is crossing the street on the other side). Better designs likely wouldn't fit without raising the cost a huge amount.