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.
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.
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.
[0]: https://en.wikipedia.org/wiki/List_of_countries_by_traffic-r...
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.)
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).
The European way requires half as many signposts, and at most half as much stopping and starting of cars.
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).
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.
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!)
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.
[0]https://en.wikipedia.org/wiki/Roundabout#Turbo_roundabouts
They make slow or medium traffic flow smoothly. If the traffic is heavy, roundabouts make everything worst.
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.
What usually happens is the roundabout gets traffic lights.
1. https://en.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hempst...
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. (-:
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.