There are more positives. - They keep traffic flowing better so you won't get "platoons" of cars all moving and stopping at the same time. This is especially effective when you do this in a sequence of intersections. - They calm do down traffic by forcing cars to slow down. - You don't need to install and maintain traffic lights.

I live in the UK, which has roundabouts, mini roundabouts, double and triple roundabouts, traffic-light controlled roundabouts, and magic roundabouts. They work perfectly fine.

The difference is that traffic flows very differently in the UK to the US. In fact, the way traffic flows in those two countries captures a lot of their cultural differences. In the US, everything needs a grand overarching theory and imposed order, which is why Americans need traffic lights, and why they’re so keen on a very specific set of liberties that allow them to freely live such similar lifestyles. The UK embraces mild chaos and ruthless pragmatism, with everyone finding locally optimal solutions to their own problems, so things like roundabouts fit well with the national mindset.

As someone who drives manual, and so actually having to downshift myself when necessary, I would rather negotiate a larger roundabout 100% of the time than having to stop at a red light 30% of the time.

On my current gearbox, I can dip to around 30 km/h and gently accelerate while staying in 4th gear, which I'd be in up to around 50 km/h. So if I hit an uncontended larger roundabout that takes me 50-30-50, I don't have to do anything, transmission-wise.

Manual driving culture is probably one reason roundabouts have been popular in Europe long before North America started to warm up to them.

> the bulk of traffic all needs to slow down, downshift, turn a bit in one direction and then turn a bit in the other direction for the minority of traffic that's bleeding on or off the main artery.

Slowing/calming traffic like this is a good thing. Make it impossible to speed. Enforce the existing 35mph speed limit via concrete rather than allowing cars to rip through a yellow light at 70mph. You're also ignoring this aspect when you call roundabouts "(mostly) worse for cyclists and pedestrians".

I think that's overly negative. Roundabouts have their place, mostly for low traffic intersections, but I agree that they tend to be overused, also here in Europe. Two examples where roundabouts are not the right solution:

- when there is too much traffic: if there is a constant stream of cars in the roundabout so you have to wait for a long time before being able to enter it, or force your way in (risking a fender bender), that's

- when you actually want traffic to flow. My small city has built a bypass road which is however IMHO completely botched: it starts with a roundabout, and the first exit leads to the route going through the center, only the second one goes to the bypass, so people are more likely to drive through the town. And it has three more roundabouts along the route, further making the option unattractive (in addition to a relatively low speed limit of 60 km/h and several tight curves).

Roundabouts do not need more space.

You can draw a circle on the road and have “roundabout rules” without the need for any car to even turn their wheels.

As a bicyclist and pedestrian (in Denmark) what is it that’s worse about roundabouts for me? I think they work really well.

> They work where each direction has an approximately equal amount of traffic. However, usually, one direction (north/south, say) has a larger share of the traffic. In those cases, the bulk of traffic all needs to slow down, downshift, turn a bit in one direction and then turn a bit in the other direction for the minority of traffic that's bleeding on or off the main artery. In those cases, a traffic light is better because the timing can be adjusted to the proportion of traffic from each direction (and more flexible since it can be adjusted over time).

This point is so under-appreciated. Roundabouts are really good in some cases, but they're over-utilized in England. Imagine if the US had roundabouts on the interstate and you're getting close.

It would be interesting to know your (friend's) country of origin.

I live in the US and roundabouts simply don't work.

Thank you so much for putting into words what I have feeling but struggling to verbalize. (Boston area, drive for work.)

There is one more downside, they are easy to get lost in, especially in an unfamiliar area. Apple Maps does an OK job guiding me most of the time, but just yesterday I spent an extra 25 minutes going through the same roundabout 3 times before I went the right direction, and each time I had to drive the wrong way, turn around, and then negotiate the same roundabout again.

You only need one roundabout to be able to drive for hours without seeing a traffic light. It’s one of the main features of loops.

> Guess what works better and barely has any traffic issues at all.

The one that where mass transit works better.

But yeah, a city still needs cars, and roundabouts are still unbeatable in low-traffic crossings. But they are not the most impacting change a city can make.

As a bicyclist I hate them, at least the smaller ones. Because they slow me down, can't take them with 40 to 50 kph, need to slow down to 30. But that was the intent, yes?

However, crossings with traffic lights I can take at any speed I'm able to, when they are green for me, and I don't need to turn. Or if I can oversee them from afar, and they are empty, and I can give a shit about 'lights'.

You almost missed it!

The footprint is a cost problem once. They don't need power, computers, or technicians to come out and maintain the equipment constantly.

You forgot roundabouts with traffic lights.

Here’s one in Australia near Perth:

https://youtu.be/h8lhX9Q6Z5g?si=eloUWLcH8q3eJiZH

And I’m certain I’ve driven through other roundabouts with traffic lights in other states.

A roundabout can be as simple as a circle painted in the middle of an intersection, plus a bit of signage. It doesn’t have to be a big thing.

I wish local councils wouldn't insist on putting in shrubs that block the line of site across the roundabout.

I've lived some places where 4-way stops were just abused, like Sugarland, TX. England and Ireland are full of roundabouts, some of which are incredibly small, just a painted dot, and some are giant multi-lane white-knuckle nightmares. There are places with good traffic light setups, but traffic lights generally suffer from the same problems of sometimes stopping traffic for no good reason while also encouraging excess speed.

In my current city, I can identify at least 3 intersections that would be better as a roundabout, but I don't have my hopes up.

They replaced a intersection near me that would get backed up very badly during rush hour with a roundabout that has a much higher capacity and never seems to get backed up.

Nowadays, depending on your state, they're being built in almost every new intersection that would call for one. And the worst existing intersections converted to them. It's happening and will only speed up.

They’re being used often in new construction areas. It’s just not likely that they’ll be retrofitted to existing areas due to needing more space than regular intersections.

They are everywhere in the areas around me now. I had a similar sentiment at one time and now they seem pretty common.

I think roundabouts work fantastically well in some places but in others they are unnecessary and in others don't work as well as alternatives. Maybe that's obvious but every so often I feel like they are overapplied — probably because of what you're mentioning, along with the fact they were underapplied in other areas in the past. I've come to like them usually but sometimes it feels like the civil engineers were having too much fun at the cost of practicality.

Roundabouts are much more common in the US than they were 10 years ago.

[delayed]

Appreciate indeed. Thanks for the reference

Two lane roundabouts are fantastic if you’re familiar with the intersection. If you’re not it’s too easy to get shunted out of the roundabout early

A major reappraisal is currently happening in the entire industry, which for too long has been focused solely on the throughput of single-occupancy vehicles. Roundabouts offer many advantages over traffic signals, even the ones that "outperform" them. It's probably a good thing that we've stopped listening only to transportation engineers focused on moving cars as quickly and efficiently as possible.

Not quite. It has to be a 4-way yield and you have to make your left turn after the painted dot/concrete hemiball, not across it.

This is completely wrong. Well designed roundabouts work very well.

The big difference is that when you have a collision at a 4-way or 2-way stop, it is almost always a "T-Bone" collision, where all the energy hits at a right angle. These collisions kill, especially at speed.

A similar collision on a roundabout is almost always a "glancing" blow, at an angle, and rarely causes injury or death.

Roundabouts force you to slow down when approaching. Stop signs can be ignored. Roundabouts can't.

The advantages aren't "theoretical." It's 100% proven that they're safer, cheaper over the long term, and flow more traffic than a red light.