Where is this oversized (and traffic jammed) traffic circle?

That’s a bit of an exaggeration. There are some regions with few to no roundabouts, but they’re not 1000 miles across. Not counting roadless areas, the largest roundabout-less area is in Wyoming (except Cheyenne), western South Dakota, and western Nebraska, but even that has a smattering of roundabouts. Here’s an interactive map of roundabouts. At that initial scale, it looks like there’s none in WY and SD, but if you expand it, you’ll see there are a few there.

However, your point is a good one. A drivers’ ed class will not want to go more than maybe 10 or 15 miles to get to a roundabout for practice, and there are still quite a few of places further than that from a roundabout.

Thanks for the cool link.

I’m guilty of delivering old info. They’ve proliferated a bunch since I was last reading up on these things. Though they’re real sparse in much of the country; A driver might be near one, but have to go a long ways to find another. Around here it seems you’re never more than 10 miles from one, but you’re often 3 or 4 miles from one with another 4+ miles to the next.

Interestingly, about 2/3rds of the ones here in metroblob SoFL are in recently constructed higher-end suburbia; the kind with large houses on large lots. I wonder how common that scenario is elsewhere? I looked around where I used to live in the Midwest and there was some similar correlation.

It’d be interesting to see a plot over time and watch them spring up like mushrooms after a rain. That map supplies a filter by date completed, but it appears to only work correctly for single years; you can’t enter “1900-1930” or “<1930” and have it work.

Thanks to covid, a friend’s daughter just had to have a paper saying she passed a class and did some driving with an instructor, show up at the DMV to get her license. No driving test. Anytime in the next two years though she can be required to schedule and show up for her driving test or her license gets revoked / suspended.

On the tangent as to US driving education:

I was born in 1981. The summer I was 15 I went to driver education at a local high school, but not the high school I went to nor the one I would have gone to if I hadn’t gone from public school; I instead went to the one where I could walk to and from my mother’s place of work. However, that was the same school district as the one I lived in, so it might have been paid for by taxes; I wouldn’t know f sure.

At the end of that course of instruction, I was able to walk right in and get a learner’s permit, and when I turned 16, I got my license, with only written tests. Apparently graduating from that program met the state’s requirement for a driving exam. And certainly on the last few days of that course, there was extra time allotted to get those slow on the uptake (which included me) to get their skills to the right point before being allowed to drive in cars without co-pilot brakes.

Or at least that’s my memory of it.

As to the topic at hand, I always found the idea of two-lane roundabouts a bit strange. I don’t see what adding a second lane really does in a roundabout, because you really can’t have two cars traveling side-by-side - the one on the inside is going to need to get off pretty soon, because they aren’t that big. The only roundabout I regularly take I will be making a left (where traffic drives on the right) at every time (I only take that route one direction), and I’m always concerned someone coming from the opposite direction as me will cut off my exit because they have the outside lane to go in and the signs say when making a left you use the inside lane. It’s definitely happened before, probably with people used to traffic circles, which are much larger. We were definitely told about the difference between them in driver’s education, but is was pretty much irrelevant because there weren’t any in the area at the time, though plenty have been added since then. I do remember seeing Rotaries in New England before that, but that wasn’t when I knew much about driving so I didn’t pay much attention.

If people use the correct lane and yield to traffic in all lanes when entering, there won’t be any conflicts, even with cars that are side-by-side (the only way you’d be directly beside a car is if it entered at the same point as you, and it won’t be crossing your path if you both obeyed the lane instructions).

But the part about yielding to all lanes doesn’t seem to come naturally. One of the first multi-lane roundabouts in my area had to be reconfigured after a few years so that there was only one through lane in each direction (the outer lanes had been straight/right, they re-designated them as right-only and added bollards where those lanes had gone through).

They certainly have proliferated in the Northeast. The bad-old days of confusing huge traffic circles with inconsistent rules are fading.
On a regular basis I see familiar intersections being replaced with modern roundabouts.

There is an intersection near the town where my kids went to school that had a horrific accident some years back.

The intersection used to be a main road with 45mph speed limit and a cross road with stop signs. A school bus at the stop sign didn’t yield right-of-way to a dump truck and they collided, killing an 11-year-old girl and injuring multiple children.

This accident spurred on the replacement of the intersection with a modern roundabout:

The work gained national recognition:

I remember the tragedy every time I drive through that roundabout, and I also am thankful for the ease of travel through that intersection. It really is much safer and easier to navigate now.

Statistics show that your typical roundabout has a small reduction (circa 30%) in collisions but a huge reduction (90%) in fatal accidents. The collisions are lower speed and tend more towards glancing rather than a bone-crushing, high-speed T-bone.

We have two intersections within 15 km of each other both with similar traffic and flow patterns. One has a roundabout, one is a 4 way stop. During peak traffic the 4 way is always congested and it astounds me that a traffic engineer signed off on a 4 way on a highway! It defeats the whole purpose of the road!

Some of those roundabouts, and particularly the Swindon one, look like Mandelbrot sets.

We have one of those in Colorado Springs, as well. It’s guaranteed to be on my route when any visitors from out of town want to see Garden of the Gods, with the simple instruction, “Things get weird, just stay in your lane and follow the car in front of you.” No one has followed on to an on-ramp so far, so it’s worked fine.

I drive through a roundabout on my way to and from work. Every now and then someone doesn’t catch on to the flow (or right turn only in right lane, left lane only goes straight or left) that catches me off-guard, especially as I need to merge left to catch my NEXT turn immediately after. The vast majority have a passable handle on the situation.

There’s a section of highway 60 in Wisconsin that has four roundabouts in the space of two miles. I definitely haven’t driven the entirety of the state, but I haven’t seen another anywhere.

The vast majority of collisions on roundabouts here are caused by someone changing lanes without looking. It frequently happens when someone in the outside lane carries on round, while a driver to their right cuts across assuming that they are taking the same exit.

Another major cause (and I did it once) is when you are second in the queue to enter a roundabout and pay more attention to looking for a gap than on the car in front - you see a gap and move forward, but the car in front doesn’t.

The latest fashion here is to use small islands at minor road junctions as a method of “traffic calming”.

Wisconsin probably has more roundabouts than any other state. The biggest concentration is in the Fox River area, from Neenah up to Green Bay. Look at the the interactive map.

There’s a fair few people around here that shouldn’t have got one, in that case, though I suspect it’s more of a “won’t” than a “can’t”. There’s one near me which, due to a combination of poor design and, well, Cornish drivers, is really really bad.

Part of the issue is that, through some act of genius, there are two junctions in town designed to look like roundabouts which are not actually roundabouts, followed by a badly laid out mini roundabout which barely looks like one.

Most drivers act as though they were at a crossroads, turning before even reaching the centre bit they’re supposed to be going round- I’ve often seen two cars coming from opposite directions, both turning right, pass on each other’s left. I’ve had loads of near misses from people pulling out in front of me although I had right of way, and I often just see people barrel through without stopping. I keep wanting to put a camera up there to really record to chaos.

Admittedly, I’ve never seen anything quite like it elsewhere in the country.

Oh, and for those who don’t like roundabouts who ever intend to visit the UK; don’t go to Milton Keynes, just… don’t.

Well, doesn’t THAT commute look like hell on earth! :anguished:

On the other hand, MK is laid out in a way Americans would find familiar, in a grid with ‘streets’ running NW/SE and ‘ways’ running NE/SW, although there are many exceptions.

Milton Keynes - Google Maps

Yeah. One of the side effects of roundabouts on main roads is they act as “traffic calming” devices.

The ones near me are on the more “major” streets within a gridded residential area. So one lane each way with houses with driveways on both sides, and a posted 25mph speed limit, just like the more minor streets in the local grid, but these “major” streets go fully across the neighborhood and have signals where they meet the boulevards at the perimeter, etc.

In any long stretch between stop signs or other obstacles people will get up to 40mph in that 25mph zone. Since you can’t negotiate the small radius roundabout at much above 20, and anything over 15 feels pretty sporty, the roundabouts mostly act to slow the average speed of traffic. Thereby protecting the adjacent intersections from quite such high speed T-bones. It takes a couple or 3 blocks for folks to get back up to 40mph. Idjits.

And, as you say, to convert what would otherwise be a pure 40mph T-bone into a 15-ish mph sideswipe at the roundabout itself.

Here’s a fun variation on the diverging diamond, the “Spooey”:

When I lived in St. Louis MoDOT was slowly installing diverging diamonds or SPUIs to replace lots of grossly inadequate and inefficient old-fashioned diamond interchanges. And they’re doing more and more traffic calming roundabouts on the minor roads. With the effect that local drivers are exposed to 1950s and 2020s traffic engineering more or less at random. Lots of opportunities for the Missouri mules to become confused and ornery. But they get it soon enough.

Here’s a fun article about the many variations of interchange. Just looking at the pictures is a trip. It’s amazing how inventive the traffic engineers have become; makes you wonder if it’s some sort of contest, like Iron Chef, to come up with ever-more elaborate ways to solve the same basic problem.

The roundabout at the Arc de Triomphe in Paris is often referred to as the most insane roundabout in the world. It was designed before cars were invented, which is bad enough. But then there are 12 boulevards converging on the circle, all of which have the right of way over cars already in the circle. There are no traffic lanes, so it seems like utter mayhem, although Parisians seem to navigate it with few problems. Also, when there is an accident, both parties (by law) are equally at fault. There are videos of the insanity.

Some people there in the middle have undoubtedly been stuck in there for years.

Regarding the “Magic Roundabout”, it was probably given that nickname because of the children’s show from the 70s? (I haven’t lived in the UK for decades but do remember the show: https://www.youtube.com/watch?v=c3DcChXNyYQ&ab_channel=AlanHilter)

About drivers in the US not being trained or not following rules, it’s all relative. I heard a young man from China express his amazement at the ease of driving in the US because drivers are law-abiding and considerate. Questioned on this, he said that driving in his city, Shenzhen, was a free-for-all, where nobody follows any of the basic rules.

We whiled away a pleasant hour on the Arc de Triomphe during rush hour, just watching the gendarmes directing cars through the mess of traffic.

It entertained the kids, and the adults as well.