paulclinger 8 hours ago

Roundabouts are great (we just had two complex intersections with traffic lights replaced by roundabouts and the traffic flow is much better), but they take significantly more space than a 4-way stop.

cucumber3732842 9 hours ago

Roundabouts excel when traffic volumes on the intersecting are comparable. They are crap when traffic volumes are highly disparate

  • orwin 6 hours ago

    They make people on the main road slow down, which is a feature, not a bug. What you mean is that they're the most efficient at what they do when the traffic is comparable. They only reduce accident at the expense of a slightly lowered throughput if the traffic is highly disparate.

  • XorNot 8 hours ago

    Right but it's not like a 4 way stop is going to perform better. In the same case you'd expect it to be a 2 way stop.

    • josephcsible 8 hours ago

      > Right but it's not like a 4 way stop is going to perform better.

      A 4 way stop does perform better than a roundabout given highly disparate traffic volumes, because roundabouts suffer from resource starvation in that scenario, but 4 way stops are starvation-free.

    • cucumber3732842 8 hours ago

      >In the same case you'd expect it to be a 2 way stop

      Which is what it was for the first 70yr... And what most of them in this particular neighborhood still are, with a 0-6mo intermission.

seanmcdirmid 7 hours ago

A lot of legacy intersections don’t have space for round abouts even in cites that embrace them.

  • masfuerte 7 hours ago

    So use a mini roundabout. They are common in the UK. It's just a painted circle with a slight hump, in the middle of a four-way junction. Vehicles can drive over it (and larger ones have to) but it indicates to everyone that they have to give way to traffic from the right and don't have to stop otherwise. They typically aren't big enough for multiple vehicles to be turning a corner at the same time. They fit anywhere.

    • seanmcdirmid 5 hours ago

      It won’t work for a four way stop with lots of traffic, it will just make things worse actually.

Mountain_Skies 7 hours ago

Even rural Georgia has double roundabouts now. Not sure why people on the internet can't contain their glee at stating the US is "allergic" to them when the frequency of roundabouts has grown significantly in recent decades.

kjkjadksj 7 hours ago

Because retrofitting them properly requires emminent domain. The ones they shoehorn onto former four way stops are so useless. They are so tight you still have to face a stop sign vs being able to just seamlessly zipper merge in a proper larger circumference roundabout. When they have room to build out a proper roundabout they are usually OK but that is hard to do outside say new suburban construction due to lack of available land on the right of way.