The city I grew up in had no roundabouts back then. Today it does have some, some were even made and removed again since. People there hate roundabouts.
The city I live nearby now has so many roundabouts that I can drive for over an hour without seeing a traffic light. It always had those, people are used to using them.
Guess what works better and barely has any traffic issues at all.
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'.
The think I don’t like about not being able to “speed” at 50kph(!) through a city is that, at least in Australia with it’s excessive compliment of bureaucratic Karens, is the 30 > 50 > 70 > 60 > 40 > 30 > SCHOOL ZONE > 80 > 40 > 50 > 30 nightmare.
Which does two things, raises state revenue and causes drivers to spend way to much time concentrating on how fast they are going rather than driving to suit the conditions and paying focusing to what’s going on in front of them.
I've got hydraulic disk brakes on several of my bikes. Though I avoid using them for such full-stops, because the places I'm bicycling in I usually know the traffic patterns, and how the lights change.
Also I'm not riding 'blindly', though if I can oversee that from afar, and it's empty, I'm pretending color-blindness.
I'm doing this since about 1980 at speeds up to 70kph for maybe up to two minutes on flat grounds
55 to 60 for about an hour, and 45 to 50 effortless, with no sweat, almost any time. Of course I feel strong head-winds, and they do slow me down.
And never ever caused an accident, just touched the rubberlip of a Citroen 2CVs rear bumper with my front wheel once at about 65.
In a roundabout ofc, because the fuckers slowed down for turning out without even blinking. Bicycle was trash, but I've been unhurt, except for very numb and tingling at the same time, hands, soles of my feet, and initial breathlessness. Which all went away after a few minutes, no bruises, no torn clothes.
After having made a salto over the handlebar, managed to separate from my bicycle in the air, pushing it aside, and landing flat on my back after 15 to 20 meters, or so.
Holding my head upright, intentionally. No tingling or numbness there.
Long live the CWU-36P Nomex Flight Jacket from about 1981. Still have that one, but with a new zipper, and new cuffs. I'm considering that thing my 'supercape' :-) And real Levis 501 as they were made in 1988!
Got myself a 'pre-owned' Bianchi with Campagnolo group the next day, for 1500 Deutsche Mark and cackled madly with joy :-)
80 to 90 downhill(on paved roads, not through the wilderness!), if weather allows, and I'm in top form. 90kph is not a good, or easy thing on any bicycle. But... speed is what I need!
Where am I even doing 90? Several places on CO82, on my way back from Independence Pass to Aspen. If weather (mostly wind, can't have strong gusts!) and traffic permits.
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.
I know of a couple in NSW: one in Albion Park, and another in Bomaderry.
They work well when the peak-hour traffic tends to block some of the entrances. You can use the lights to allow the blocked entrances to flow, then turn the lights off out of peak-hour.
Roundabouts come with this otherwise unused patch of land in the middle. Apparently, it has become common practice around the world to put some random art there, or a little green space, or a fountain, or a "welcome to this town" sign.
Agreed, it can be really hard to get around a roundabout as a pedestrian if it's not designed for it, and then they make it so both you and people entering don't know each other are there until you're about to get hit.
According to Wikipedia, these shrubs are there for a reason. Denmark has found that blocking the line of sight significantly reduces the accident rate by forcing the drivers to slow down and consider only their immediate surroundings. Danish drivers hate them, anyway.
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.
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.
Yeah, I know what you mean by abusing 4 way stops being abused. Thankfully I moved from there a long time ago.
Also where I moved from recently, they changed a roundabout intersection into a traffic lights intersection. And the traffic used to flow. Now it’s a stand still.
There’s always so many little insights when you use the road daily that a planner will never have unless they do the same.
Melbourne where I am kind of close to now, has an absolute clusterf*ck of overpasses, underpasses, toll ways, free ways, tunnels all coming & going out of a neatly planned grid. They probably think it’s planning perfection while driving it as a non-resident is an absolute nightmare. Sydney which is famously poo poo’d for not being planned in Australia is 10x more straight forward to drive.
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.
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.
This led me down somewhat of a rabbit hole looking at roundabouts, then to the official roundabout page from the Department of Transportation, where I couldn't believe my eyes to see that National Roundabout Week is next week: https://highways.dot.gov/safety/intersection-safety/nrw
National Roundabout Week should be two weeks separated by a week, so that if you missed the first week, you just wait another week and it comes around again.
I think I prefer maybe the simplicity of 4 way (or even 2 way) stops
There are some funny intersection videos from idk what country that have no stop signs or lights or roundabouts and somehow lots of people still manage to get through them
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.
I was in Aruba recently, and I discovered that they had entirely replaced their traffic lights with roundabouts. Easier to maintain and more efficient in the island's low-traffic regime.
My best friend is a highly experienced civil engineer, specialized in designing intersections. His take on roundabouts:
- They are adored by urban planners because they look nice and you can put a statue or fountain in the middle
- They reduce T-bone collisions
However:
- Small fender benders and sideswipes are much more frequent
- They use way more area
- 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).
- Finally, they're also (mostly) worse for cyclists and pedestrians.
Essentially, they have use cases, especially in small towns, and they're pretty, but they're usually not the right engineering solution.
Not much of America's traffic infrastructure works well. Every month, combined with poorly trained motorists, it contributes to another 9/11's worth of fatalities. The infrastructure you think works, kills enough people for a thirteenth month at the end of every year.
They have their downsides, but "It doesn't work in America" is more informative of American motorists than roundabouts
Yeah I regularly drive in France which has terrible drivers (road deaths way above EU average in France) but it's nowhere near as bad as the US.
The one thing people should ponder is this: Germany has less than 3x the number of road deaths (no matter how you count it: per 100 K people, per kilometer, etc.) than the US. And yet every time I'm in Germany I happily drive at 125 mph on the highway (including when I drive to Poland, where most autobahns near Dresde have no speed limit at all whatsoever). And at 125 mph, I'll get overtaken by some cars going proper fast.
So, what, 65 to 70 mph max speed limit vs unlimited speed and three times the deaths: what's the problem?
Note that I'm certainly not advocating for US (or France for that matter) highways without speed limits: drivers are way too bad.
Germany is somewhat an exception when it comes to good and safe driving though, I think they're all afraid the government will take Autobahn away from them if they drive too bad.
It's a huge difference passing through France, having near hit collisions every hour on the highway with distracted French families, arriving to start passing through Germany, and suddenly people actually use their blinkers, drive on the right side, seemingly everyone knows defensive driving, and no one is up in your ass if you're at the speed limit.
Love driving in Germany though, countries should look into how they managed to get the car culture they have. Maybe it helps the Germans invented the automobile and all that comes with that. Probably still there is lessons to be learned from them.
Legislators in the US won't cover the actual costs of road maintenance. Most cities issue long term bonds to finance road construction & repair, but in order to repay those bonds, those states & cities need to constantly grow.
Damage to roads is related to the third power of speed and the fourth power of axle weight.
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.
but just yesterday I spent an extra 25 minutes going through the same roundabout 3 times
How big was this roundabout when it took 25 minutes doing 3 victory laps in a roundabout?
You might want to petition your local government to put the signs of the exits before the roundabout, together with exit signs inside of the roundabout, helps a lot to see what exit you should take.
Alternatively, try a different map viewer, both Google Maps and Waze handles roundabouts excellently with zero issues, Apple Maps might still be too new to be useful for daily use.
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.
I think the main problem in England is that there is just too much traffic for too little road. I don't think there is a simple infrastructure solution to that problem.
For example I was going to point out that roundabout completely fail when one direction becomes nose to tail congested but when I thought about local examples, I'd rather take that over a set of traffic lights where it becomes near impossible to get out from one direction if the traffic keeps backing up onto the junction.
I think the main problem in England is that there is just too much traffic for too little road.
I think Jevons paradox basically guarantees this in both countries. The difference between the two countries (in my theory) is how much responsibility they're willing to place on the drivers. The UK requires much more driver effort for good reasons I suggest in another thread.
Imagine if the US had roundabouts on the interstate and you're getting close.
What's the problem with a roundabout on the interstate? Obviously it'd have to be huge to account for the speed, so people don't need to change speed too much, but given the right size, it'd work wonderfully.
Nothing depending on your perspective. Mine is a U.S. perspective and a disposition against. They slow things down and require more mental and physical capabilities than the U.S. approach. That’s not accidental or because U.S. people are dumber, it’s just a cultural difference between the countries in terms of driver expectations. I’ve proposed a rationale elsewhere.
They slow things down and require more mental and physical capabilities than the U.S. approach.
Make the roundabout larger then, and you can keep just about the same speed. How can a roundabout take more mental and physical capabilities and slow you down less, than a stoplight on the interstate? That's very backwards, and not sure what roundabouts you've experienced, if that's the case.
There aren't stoplights on the interstate. That was the point I was making. (It got lost in the follow up.)
But to answer your question, roundabouts always require drivers approaching from all directions to slow down, lookout for cross traffic and assess other drivers' behavior. Stop lights have 2 modes that promise safe passage, and they can be set to prioritize routes.
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.
Because the US largely "grew up with cars", the economy was built around the expectation that folks can drive to work. The population density of the US reflects this, and mass transit just doesn't work in small/middle America. That means everyone needs to be able to drive. If you can't drive, you can't work. That isn't the case in the UK, and you'll notice a lot of these "driver beware" analysis is explained by the fact that driving in the UK is seen as a privilege whereas it is a right in the US. This sort of "mild chaos" is prohibitive for a lot of would-be UK drivers, and they just take the bus.
The UK has an over-reliance on roundabouts for junctions with motorways and large roads. They are also missing out on Turbo roundabouts, which are super cool and very common in the Netherlands.
I don't want to celebrate UK roads too much. The majority of roundabout users in the UK are not indicating properly. Too many people are stopping at them when they have priority. Lanes are just a suggestion and using the correct lane is an invitation for someone to drive into the left of you.
In other areas: enough people don't know how to use a slip road that it becomes a problem to those who do. Likewise the flashing ambers of a pelican crossing. Lane discipline is much worse than on the continent, to the point you can see it creating traffic jams. Lots of people are driving big cars without the confidence needed to remain in their own lane.
There are millions of drivers who've never passed a theory test. We could do with more ruthlessness.
I feel like you're singling out UK drivers without much evidence here, I've driven lots across continental Europe, although mostly Spain<>France<>Germany<>Nordics, but in all countries people tend to not indicate properly, inside of roundabouts or outside of them. I'll admit to people in the Nordics being slightly better at signaling, but they make up by being so scared and non-confident in their driving that their hesitation causes near-accidents, rather than the opposite.
Still, all across the world the average driver seems to below what I imagined the average driver to be, before I started driving myself.
It may be user error, but that doesn't mean roundabouts aren't a footgun. It only takes one driver who doesn't do everything correctly to cause problems. It's not much fun driving around in the correct lane, only for someone to pull alongside you to the left (equivalent of "right" in the US, of course!). I failed a driving test because someone cut across me on a roundabout.
"I failed a driving test because someone cut across me on a roundabout." That driver may have cut across you on that roundabout but that doesn't mean roundabouts are a footgun.
I mean, what you're trying to minimise is (frequency of misuse x consequences of misuse). signalised intersections target the frequency element, roundabouts target the consequences.
When comparing two interfaces and one allows a larger amount of user error that interface is inferior.
The point is roundabouts require more work to navigate correctly than a four way intersection with traffic lights. Thus drivers are more likely to navigate incorrectly.
When comparing two interfaces and one allows a larger amount of user error that interface is inferior.
Seeing a safety issue and ignoring all other considerations is an excellent example of the ‘overarching theory and imposed order’ I argued that Britain rejects in my first comment.
Not gonna lie, I know about the flashing ambers of the pelican crossing, but they are uncommon enough, whenever I see one, I spend several seconds wondering what is happening, until it clicks it's one of these crossings.
Try Spanish roundabouts. On the whole, poorly designed, implemented and regulated. On roundabouts with two or more lanes, laws favour those on the outside lane, so everyone takes the outside lane even if they are travelling 3/4 of the way round. As a result drivers who are in a position to take an exit, do not take that exit. In addition, indicators are not used by most drivers, or they simply leave their indicators on all the way round. In addition, it is not allowed to exit a roundabout from the inside lane even on to a two lane exit. In addition many roundabouts have three lanes to enter onto a two lane roundabout, or two into one, etc. No one knows the rules, or follows them, and no one seems to care, from the civil engineers right down to the end users. The only winners are repair shops.
In comparison, UK roundabouts are civilised examples of harmonious intellectual etiquette. Enjoy them.
[source] I learned to drive in Swindon, home of the Magic Roundabout.
I live in the UK, drive occasionally in Spain due to Spanish in-laws, and agree wholeheartedly. I didn't know about the "outside lane has priority" rule though. I'd noticed it happening, but just thought it was a national quirk rather than gaming the system.
American, in an area getting more roundabouts. The two most heartfelt criticisms of roundabouts I've heard are:
- I have to pay attention every time I go through one. (Vs. having your mind elsewhere works fine with traffic lights? That might explain some of those T-bone crashes.)
From my PoV, roundabouts are generally a good thing. Mostly because local engineering standards for traffic lights are wretchedly low - so I can get where I'm going far faster through roundabouts.
As a European, that roundabout intersection looks fine? It might be slightly annoying to have to use all three roundabouts if you're exiting the highway northbound and want to take the southbound local road, but with the amount of exits there I can't imagine a junction would be better.
The fact that you mention light-controlled roundabouts highlights that they do not, actually, "work perfectly fine".
Roundabouts are a practical example of the tyranny of the majority; minor traffic flows suffer against major. The centre of Salisbury is a perfect example, constantly gridlocked at two roundabouts except at odd hours on a Sunday.
Adding traffic lights to 'fix' this problem then leads to tailbacks on the major routes and congestion on the roundabout, such that the timing sequence for the minor routes are subsequently reduced, returning to the original problem.
Roundabouts, in the plurality, are used as a lazy 'solution' to at-grade traffic crossing, which the road designers themselves presumably don't have to suffer. They also cause pollution from brake dust from slowing and exhaust fumes from accelerating.
The fact that you mention light-controlled roundabouts highlights that they do not, actually, "work perfectly fine".
I don't think anyone is claiming that roundabouts work in every and all situations: design handbooks often say they're good 'up to X vehicles per hour/day'.[1] But that does not mean they do not work, or not useful, for <X.
Intersections are an engineering problem, and there is a hardly ever an engineering solution that works everywhere and always. There is usually a spectrum of solutions for the various situations that are faced.
Well we have very different experiences driving to, through, and around Salisbury. There's traffic, and it can get bad, but it isn't as bad as you say.
The council and national highways are working on it, but the problem is not one of roundabouts - its one of increases in traffic and lack of capability to make the roads bigger and/or build a bypass. Unless we're willing to knock down a load of housing and cultural sites we're stuck with something around or slightly more than the road capacity we have.
In very heavy traffic conditions I suspect that roundabouts can gridlock all directions in a worse way than a standard intersection with a yellow box because everyone tries to enter the roundabout then they get stuck in it, and then the whole traffic is brought to a halt, including directions that should be unaffected. This happens very often where I live.
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".
However there are often pedestrian crossings across the roads or the volume is low enough pedestrians can easily cross. A local roundabout got busy enough we had crossing added less than 10 years ago and the biggest road there was a minor B road.
I am a pedestrian due to sight issues and have found very few places where it is difficult to cross when needed.
This is true if you can alter the properties of the physically existent universe, else it is not true, and, indeed, drivers do not even slow down largely because they feel frustrated when traveling along a road with a 45 MPH speed limit at an average speed of 20 MPH.
becomes congested with no time/space gaps between vehicles, is worse for pedestrians
Why? This feels like it's assuming pedestrians share the street with vehicles, but besides the US and some other places, don't most "modern" countries have separate pavements/streets for pedestrians? Besides in the country-side, vehicles and pedestrians don't generally share the road in populated areas here in Spain. For crossing roads outside cities, building a pedestrian tunnel below or a bridge above seems to preferred here, except in the cases where it isn't possible, and in cities obviously.
Right, you're talking about "traffic participant", are you including pedestrians or not? Because as I said, in many places, "vehicles" and "pedestrians" are well-separated and don't impact/affect each other, so not sure what cluster-fuck could be created there. Seems less of a cluster-fuck than relying on cross-walks and stop-lights?
There used to be an epidemic of cars striking and killing pedestrians. The advertising industry (hired by the auto industry) came up with the new imaginary crime called "jaywalking". This diverted attention from the killers and onto the victims. Just one more version of the victim blaming that derives from the Just World Hypothesis.
A 1993 study in the Netherlands examined collision experience at 181 intersections converted to roundabouts. Pedestrian collisions (all injury severities) dropped 73% and pedestrian casualties dropped 89%.
Evaluations in Sweden concluded that single-lane roundabouts are very safe for pedestrians, at about a 78% reduction in injuries, and that multi-lane roundabouts are about as safe as other intersections.
A 2002 study of collision experience at the roundabouts in Park City, Vail, West Vail and Avon, Colorado, showed 2 pedestrian crashes prior to the roundabouts operating with
over 164 million vehicle movements, compared to 1 pedestrian crash with roundabouts experiencing over 282 million vehicle movements.
With the installation of a roundabout, this study finds that the before-after analysis results in a 40% decrease in all severity injury crashes for all roadway users, a 70% decrease in fatal and serious injury crashes for bikes and pedestrians, and a 15% decrease in total pedestrian bike and pedestrian crashes.
OK, so "worse for pedestrians" boils down to a statistic about body hits. If you are not struck, you are not having a worse pedestrian experience. My bad!
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.
Platoons of cars with space in between allow for pedestrians and vehicles to cross the road, downstream.
Nothing worse to have upstream of where you are trying to enter a road, or cross it, than a busy four way stop, with cars coming out of it at regular intervals, without sufficient time/space in between.
I think to an American, a roundabout is this thing that only works for cars and don't take pedestrians or bicyclists into account, with no paths or crosswalks or anything, so hence "Worse for pedestrians". I don't blame them, both roundabouts and care for pedestrians seems uncommon over there, so of course their experience will point towards roundabouts being worse overall.
(UK experience) If you're trying to cross the road leading onto one, it's much harder to tell if a vehicle is going to hit you at speed. I often observe people turning quickly, without indicating, and had I chosen to cross at that time, there would have been some kind of accident. Junctions tend to not have this problem since cars turning out of them are usually going much slower.
I will say 2 lanes roundabouts as a cyclist are a little intimidating when you need to take the inside lane. Drivers are not looking for cyclists the way they look for cars or will rush to get ahead of you or just try to bully you out of the way by entering the roundabout across you illegally and daring you to take the right of way. At particularly busy examples I will dismount and take the pedestrian crossing.
Junctions have their own problems though: Usually drivers will not permit a cyclist to merge in front of them while traffic is not stopped, which means if the stream of traffic is continuous you need to plan your lane change when traffic is stopped by lights.
As a pedestrian, roundabouts with islands (aka all roundabouts here) are vastly superior.
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).
- 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
I think it's fine with lots of traffic in a roundabout, but it has to be somewhat balanced.
For example, we have a roundabout that sits on a relatively popular road, with one exit/entry that leads to a bigger highway. During rush hour, there is heavy traffic, from from/to every one of the three points, so traffic naturally divides, as cars turn off.
However, when there is no rush hour, the highway exit/entry isn't used, so cars mostly just pass through the roundabout, and everything still works, as the two entries/exits are still balanced.
Issues would arise if it's only one entry/exit being used, as then it'd always block the two other entries from being used properly, but seems that never happens, so seems to me it's proper and works well, regardless of the traffic being heavy.
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.
I don't understand the argument? Seems like you're saying that not having to handle a gear change makes roundabouts better, but that applies to both your manual technique and automatic, so I don't see how Europe would be different from NA?
Also, I'm not a particularly frequent/experienced driver but 4th gear at 30kmh on a roundabout doesn't seem very safe, it does not leave you much control to react to something unexpected (some car coming up that you didn't see, a car who changed their mind last minute about exiting, a car changing lane poorly...). Being able to decelerate or accelerate quickly is pretty important on a roundabout. Not such a big deal on a very big roundabout with excellent visibility where there's no-one, but that's pretty rare in europe at least.
Rather, what I don't understand is the original argument that roundabouts are bad because the busy direction of traffic has to slow down and gear down unconditionally, whether or not the rare cross traffic is present, so it is then better to have a traffic light there.
The "you need power to accelerate out of danger" is a motorcycle argument (and a pretty flimsy one); in a car, you are not gas-pedaling your way out of anything. Your emergency control devices are brakes and steering, that's it. There are moves that powerful acceleration lets you get away with, and they are all reckless, and often built on the assumption that only you have that acceleration. People are now using their high-torque EVs like this. You will never be in a collision close call caused by someone or something doing something unexpected, where the reaction of stepping on the accelerator is the action that saved the day. Can't deny that it could help run from a tsunami wave or fire or something.
Not a civil engineer but as far as I know, the space is part of the point. If you keep the roads straight but just draw a circle in the middle, you don't have a roundabout. It only works properly if the drivers have to curve in and out of it.
You could keep the same space I guess by pinching the roads tighter near the entries/exits but I don't think anyone is talking about that.
I contest that drivers always treat it the same. They often go through the circle/cut th corner when there is low traffic, and I know at least one mini roundabout where traffic is way less frequent in one direction and the other direction is treated as the "main road" without slowing down.
You can draw a circle on the road and have “roundabout rules” without the need for any car to even turn their wheels.
If it's physically possible to "skip the roundabout", if it's just a drawing rather than hard barriers, people here (Spain) will just skip it straight up, unless there is a ton of traffic. I think lots of these driving rules and infrastructure has to take local culture into account, as it differs from "We follow laws like our collective lives depend on it" to "We see laws more like suggestions" depending on the country.
That approach fall down flat on nontrivial traffic amounts. Also it requires an actual hindrance in the middle to enforce compliance, and then bigger vehicles won't be able to turn left.
In Sweden they have these huge roundabouts in the countryside. Very large diameter and gentle curves. You can maintain your speed. Awesome. Saves energy too. I assume there's a huge amount of tried and tested traffic innovation that could be directly just copied.
In Spain we have these two, sometimes right outside metropolitan areas, that see a lot of daily traffic, especially around rush hour. They're naturally balancers, if you plan them correctly, makes a ton of sense to default to roundabouts instead of stoplights.
Especially nice for us who plan our car trips based on when there will be the least public traffic out there, as roundabouts don't force you to stop when there is no traffic, and you can essentially keep the same speed with these large roundabouts.
Small fender benders and sideswipes are much more frequent
Do you have any data on this? Everything I've ever read about them points to exactly the opposite conclusion. They actually reduce accidents and by a significant margin.
My only guess would be that you are referring to the US, where people are not used to roundabouts and yielding without a STOP sign.
they're also (mostly) worse for cyclists and pedestrians
For cyclists, this is mostly true IMO (depending on implementation), but for pedestrians roudabouts are way better than traffic lights. In the absence of lights, pedestrians have right of way on crossing, so no waiting time, and physically slowed traffic make it safer.
but for pedestrians roudabouts are way better than traffic lights.
This is ignorant texbook thinking.
As a pedestrian it's far easier to safely time a light, even one without a cross signal, than it is to cross through the un-broken streams of traffic that are entering/exiting a roundabout. You basically have to cross a ways back from the roundabout where the traffic is more like "just crossing a normal road". Which sucks if it's 4-lanes or really busy or fast or there's no sidewalk provision for that (like in the case of roundabouts at highway ramps) and is just a lot more walking to begin with.
For roundabouts that wouldn't be deserving of a light (i.e. the ones replacing 2/4way stops) it's a lateral move.
The point is that traffic streams are not unbroken: when there is a crosswalk and cars are obliged to stop in front of it in the presecence of a pedestrian, then the flow is broken.
Just blundering up to crosswalks because "they have to stop, hurr durr it's the law <foams at mouth>" results in a substantially more hazardous pedestrian (and driver) experience than timing your approach and using your body language so that the drivers know what you're gonna do and can take action to hedge against it.
Especially with heavy traffic, the traffic all slows down, a lot, from the section before the roundabout. Everyone is always in a hurry, so likely 10-25 MPH over the recommended speed (not the speed limit) for the roundabout, and all of them are at a 6 foot following distance.
You are playing with death to step into that. It's no joke. You end up effectively waiting for the upstream light to turn red so traffic can clear and you can cross.
The only solution I've thought of is to put a large grocery cart full of paint buckets at the roundabout for pedestrians to push into the crosswalk without risking their own lives.
Which sucks if it's 4-lanes or really busy or fast or there's no sidewalk provision for that (like in the case of roundabouts at highway ramps) and is just a lot more walking to begin with.
I mean, it depends on your standards for roundabout. We didn't put highways through town centres so largely highway ramps and pedestrians are mutually exclusive scenarios here. Where pedestrian crossings exist, there's usually (a) an island and (b) 2 lanes prior to the island, splitting to 4 lanes either where the traffic is already slowed or past the island, which makes it much more pleasant than crossing at an equivalent junction. Also as a driver, it means you've cleared the pedestrian area before you have to consider/deal with the cross direction drivers as there's a small waiting area post-pedestrian-crossing/pre-roundabout.
If you're stuck because you already have a highway in your urban core and need pedestrians to safely cross the highway, then you are pretty much limited to overpasses and underpasses.
Depends on the driving culture and familiarity with roundabouts for sure. Moved from the US to a city in Norway with almost exclusively roundabouts, and it's _so much nicer_. Even in the edge cases, I have never once found myself wanting a traffic light.
Simple intersections can have very small roundabouts, and bigger ones you can connect roads from so many weird directions and have traffic flow well that I would never want to return some of the intersections I experienced in the US.
The "use more area" needs to be considered in the sense that, designed properly, they eliminate left turn lanes and "suicide lanes" in the center of the road.
Instead, with proper design, you make this "left turn" by going to the next roundabout, going around to follow the road the opposite direction, and then make a right turn.
It's also only true when compared against a no-frills intersection. A two-lane roundabout has better overall throughput than a two-lane intersection with traffic lights. To increase throughput, they usually add turn lanes to avoid cars having to stop in the through lanes -- but the turn lanes require more road surface than the roundabout would have.
That would generate stronger agreement if the bad drivers’ struggles mostly affected them. Instead, their chaos radiates outward significantly onto those who know how to drive.
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.
While it would slightly defeat the purpose in some ways, roundabouts with traffic lights are a thing:
So if one way has heavier traffic (at times), things could be signalized to allow (e.g.) that one direction primarily some of the time and the other three directions the rest.
Finally, they're also (mostly) worse for cyclists and pedestrians.
Some data seems to conflict with this:
A 1993 study in the Netherlands examined collision experience at 181 intersections converted to roundabouts. Pedestrian collisions (all injury severities) dropped 73% and pedestrian casualties dropped 89%.
Evaluations in Sweden concluded that single-lane roundabouts are very safe for pedestrians, at about a 78% reduction in injuries, and that multi-lane roundabouts are about as safe as other intersections.
A 2002 study of collision experience at the roundabouts in Park City, Vail, West Vail and Avon, Colorado, showed 2 pedestrian crashes prior to the roundabouts operating with
over 164 million vehicle movements, compared to 1 pedestrian crash with roundabouts experiencing over 282 million vehicle movements.
With the installation of a roundabout, this study finds that the before-after analysis results in a 40% decrease in all severity injury crashes for all roadway users, a 70% decrease in fatal and serious injury crashes for bikes and pedestrians, and a 15% decrease in total pedestrian bike and pedestrian crashes.
My main two cons with roundabouts are that one, when you have those residential streets where basically every intersection is a roundabout so you get many of them in a quick sequence when you’re going straight all that centripetal force is annoying to deal with.
And the second thing is when you have very large roundabouts, there’s always a bit of chaos involved between shifting lanes from the innermost lane towards the outermost lane because I’ve noticed people don’t enter the roundabout on the right lane, so there’s always a little bit of chaos during the crossover.
The key disadvantage of a roundabout is that it takes up more space and is harder to setup than plopping down a couple of stop signs.
They are awesome otherwise, I do like them better for low traffic intersections though because I don't have to stop and think about if the next car is going to yield or not.
Only large roundabouts take space. Small roundabouts can easily be retrofitted into small, unguarded residential neighborhood intersections without clawing back any sidewalk corners. They just plop a curbed-off circle in the middle of the intersection, leaving a narrow passage around it. Now a car going straight has to swerve into a crosswalk that is going in the same direction. Massive win!
I think here in China we are not super fan of roundabouts. But we got a 4-lane roundabout with traffic lights [1] and a roundabout on elevated roads with traffic lights. [2]
Roundabouts are the Segway of civil engineering. In theory, a game changing transport innovation. In practice, just a little too mismatched with everyday aesthetics to properly fit in. Dorky and annoying for pedestrians too!
Good old traffic lights have a much better feature of being able to control traffic to allow for pedestrians, give cyclists a head start, give smaller side roads a look in at busy junctions, and giving a platform for traffic monitoring.
It's so funny seeing most of the comments, plus the original article, implying that roundabouts are always better or always worse than traffic signals. As someone who used to be a Transportation Engineering professor, they have a time and place where they outperform traffic signals but it's definitely not everywhere. It is known and there are many traffic simulation software tools that will give you a pretty good indication of what will happen if you put a roundabout here or a traffic signal there.
This thread reminds me of when my libertarian friend was explaining to me how traffic shows how everything can work well when everyone acts in their own self interest. Well, sure, except for all the traffic laws, the difference between User and System Optimal that traffic engineers spend much of their lives trying to bridge, and, you know, the fact that it took an enormous effort by government to build smooth roads and put up signs everywhere. Sigh. I'm not saying Transportation Engineering is the most important, innovative field, but funny things happen when not transportation engineers talk about transportation systems.
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.
my libertarian friend was explaining to me how traffic shows how everything can work well when everyone acts in their own self interest. Well, sure, except for all the traffic laws, the difference between User and System Optimal that traffic engineers spend much of their lives trying to bridge, and, you know, the fact that it took an enormous effort by government to build smooth roads and put up signs everywhere.
Love this.
Likewise "free markets" which work great when embedded in a system of laws and regulations. Or more critically, in a high-trust system where people keep their word because that's what matters.
But not sure how many people are in favor of the more unregulated black markets, where contracts are enforced by rule of violence instead of rule of law.
As if we've forgotten Hobbes, and the horrors he lived through which informed his philosophy.
You're missing the variations where you have stop lights to go into the roundabout or the even worse variant, roundabouts that are large enough to have 3-4 zones of stoplights inside of the roundabout itself!
I'll take a roundabout any time of the day, but then I mostly to drive out in the public when the traffic is the least, so any stop lights tend to be more annoying that useful.
Streetcraft on Youtube compared 2 similar routes, one with roundabouts and one with traffic lights. They found roundabouts to be quicker and more fuel efficient: https://www.youtube.com/watch?v=012fMI3TdRo
Surprised Carmel, Indiana hasn’t been mentioned in article or comments. They replaced almost every single stoplight and stop sign intersection in the town with roundabouts. Think the number of roundabouts in the town is in the hundreds
In France, if you move up too far, you can no longer see what color the light is — consequently everyone waits back where they should.
Not sure this will stop people. In Spain we have the same, the stop lights go before the pedestrian zebra thing, yet still some people think you're supposed to stop on top of the zebras, beyond the stoplight, then they wait for someone behind them to blink. No, makes no sense to me either.
I enjoyed driving around Lanzarote in the Canary Islands because you'd occasionally see roundabouts with wind-driven sculptures by César Manrique - e.g. https://maps.app.goo.gl/mzK8by7shYJ2yvYC9 - an artist who lived there.
These don't work in the U.S. as everyone fantasizes they do.
An important note: in the U.S., the vast majority of jurisdictions permit making a right turn on a red light, and some, including the state of Oregon, permit making a left turn onto a one way road from a red light. In high congestion areas, such as here in Las Vegas Valley, many drivers will not fill a right lane at a red light when they are not turning right as a courtesy to those needing to turn right at the intersection.
During commute hours, everyone disobeys all laws to get home or get to work. When there are regularly spaced roundabouts on a long stretch of road, drivers get exceptionally impatient and will drive at the performance limits of the vehicles, late-braking like they are F1 drivers. This ends up grouping all of the drivers into a very solid wolf pack who will not stop for anyone and will speed through the roundabout, making it impossible for pedestrians and drivers other onramps to enter the roundabout.
The vast majority of drivers do not know how to use the roundabout, as is evidenced when they enter from the left lane of a two-lane road and use the exit lane that is only marked for use from the right lane. Americans who know how to use the roundabout respond to this by habitually stopping at the roundabout entrance when they see a car in any lane entering the roundabout at high speed, which is most vehicles. Then the drivers behind the stopped vehicle think the stopped vehicle is driven by someone who doesn't know how to drive on a roundabout and begin honking incessantly or attempting to illegally pass the stopped driver.
Henderson, Nevada provides many such examples of this. Most interesting to me is that parts of the town have nearly identical roads that are served by either only traffic signals or only roundabouts. My experience is that the roads with traffic signals have far fewer issues than the roads with roundabouts.
The city I grew up in had no roundabouts back then. Today it does have some, some were even made and removed again since. People there hate roundabouts.
The city I live nearby now has so many roundabouts that I can drive for over an hour without seeing a traffic light. It always had those, people are used to using them.
Guess what works better and barely has any traffic issues at all.
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'.
Some roundabouts here have bike pass troughs on the side (obviously only works if there is no turn to that side) for speedy drivers like you.
Other than that it's obviously by design. There is no reason to speed at constant 50kph in a city. Nether for a car, motorbike or e-bike.
The think I don’t like about not being able to “speed” at 50kph(!) through a city is that, at least in Australia with it’s excessive compliment of bureaucratic Karens, is the 30 > 50 > 70 > 60 > 40 > 30 > SCHOOL ZONE > 80 > 40 > 50 > 30 nightmare.
Which does two things, raises state revenue and causes drivers to spend way to much time concentrating on how fast they are going rather than driving to suit the conditions and paying focusing to what’s going on in front of them.
And don’t get me started on the pot holes.
Well, provided you can still stop in time should the lights begin to change.
I've got hydraulic disk brakes on several of my bikes. Though I avoid using them for such full-stops, because the places I'm bicycling in I usually know the traffic patterns, and how the lights change.
Also I'm not riding 'blindly', though if I can oversee that from afar, and it's empty, I'm pretending color-blindness.
I'm doing this since about 1980 at speeds up to 70kph for maybe up to two minutes on flat grounds
(exception 73.5 uphill here https://www.openstreetmap.org/?mlat=50.719937&mlon=7.111630#... in the middle of two lanes between gridlocked cars, unforgettable ooomph),
55 to 60 for about an hour, and 45 to 50 effortless, with no sweat, almost any time. Of course I feel strong head-winds, and they do slow me down.
And never ever caused an accident, just touched the rubberlip of a Citroen 2CVs rear bumper with my front wheel once at about 65.
In a roundabout ofc, because the fuckers slowed down for turning out without even blinking. Bicycle was trash, but I've been unhurt, except for very numb and tingling at the same time, hands, soles of my feet, and initial breathlessness. Which all went away after a few minutes, no bruises, no torn clothes.
After having made a salto over the handlebar, managed to separate from my bicycle in the air, pushing it aside, and landing flat on my back after 15 to 20 meters, or so.
Holding my head upright, intentionally. No tingling or numbness there.
https://www.openstreetmap.org/#map=19/51.070329/6.999691
Long live the CWU-36P Nomex Flight Jacket from about 1981. Still have that one, but with a new zipper, and new cuffs. I'm considering that thing my 'supercape' :-) And real Levis 501 as they were made in 1988!
Got myself a 'pre-owned' Bianchi with Campagnolo group the next day, for 1500 Deutsche Mark and cackled madly with joy :-)
80 to 90 downhill(on paved roads, not through the wilderness!), if weather allows, and I'm in top form. 90kph is not a good, or easy thing on any bicycle. But... speed is what I need!
Where am I even doing 90? Several places on CO82, on my way back from Independence Pass to Aspen. If weather (mostly wind, can't have strong gusts!) and traffic permits.
https://www.openstreetmap.org/?mlat=39.1197&mlon=-106.5797#m...
What else? I don't wear a helmet. And no doping. Never even tried that. For what?
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.
Famous scene in Chevy Chase's European Vacation.
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.
[edit: for clarity, I am not against roundabouts]
I don't have real expertise in civil engineering
Traffic lights have a smaller physical footprint and require less construction activity.
Traffic lights fit on a cost spectrum from two stop sighs, to four stop signs, to stop signs plus blinking lights, to non-trivial signaling.
First make it work. Then make it good. Then make it fast.
Engineering is not a one size fits all discipline.
[edit: I have a background in urban planning, architecture, and real-estate development]
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.
I know of a couple in NSW: one in Albion Park, and another in Bomaderry.
They work well when the peak-hour traffic tends to block some of the entrances. You can use the lights to allow the blocked entrances to flow, then turn the lights off out of peak-hour.
In England we even have roundabouts of roundabouts https://en.wikipedia.org/wiki/Magic_Roundabout_(Swindon)
Ooo! I like that one!
I’ve driven around the Hemel Hempstead one a few times. Very confusing when I first saw the sign.
My honest take roundabouts with traffic lights are just traffic lights with extra steps.
The footprint is a cost problem once. They don't need power, computers, or technicians to come out and maintain the equipment constantly.
Land can approximately be converted to a recurring cost via rents.
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.
Or a dog: <https://en.wikipedia.org/w/index.php?title=Roundabout_dog&ol...>
I wish local councils wouldn't insist on putting in shrubs that block the line of site across the roundabout.
Agreed, it can be really hard to get around a roundabout as a pedestrian if it's not designed for it, and then they make it so both you and people entering don't know each other are there until you're about to get hit.
According to Wikipedia, these shrubs are there for a reason. Denmark has found that blocking the line of sight significantly reduces the accident rate by forcing the drivers to slow down and consider only their immediate surroundings. Danish drivers hate them, anyway.
I like roundabouts over lights at small intersections. I still prefer simple give way/stop that changes the next intersection over roundabouts.
Lights suck unless there’s sufficient traffic.
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.
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.
Yeah, I know what you mean by abusing 4 way stops being abused. Thankfully I moved from there a long time ago.
Also where I moved from recently, they changed a roundabout intersection into a traffic lights intersection. And the traffic used to flow. Now it’s a stand still.
There’s always so many little insights when you use the road daily that a planner will never have unless they do the same.
Melbourne where I am kind of close to now, has an absolute clusterf*ck of overpasses, underpasses, toll ways, free ways, tunnels all coming & going out of a neatly planned grid. They probably think it’s planning perfection while driving it as a non-resident is an absolute nightmare. Sydney which is famously poo poo’d for not being planned in Australia is 10x more straight forward to drive.
This dreaming about roundabouts is as American as the fantasies about using metric one day.
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.
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.
This led me down somewhat of a rabbit hole looking at roundabouts, then to the official roundabout page from the Department of Transportation, where I couldn't believe my eyes to see that National Roundabout Week is next week: https://highways.dot.gov/safety/intersection-safety/nrw
You almost missed it!
National Roundabout Week should be two weeks separated by a week, so that if you missed the first week, you just wait another week and it comes around again.
Author here. Wow that's amazing unintended timing!
It is so funny to read this because in reality, roundabouts are some of the worst traffic congestion makers :)
This is completely wrong. Well designed roundabouts work very well.
I think I prefer maybe the simplicity of 4 way (or even 2 way) stops
There are some funny intersection videos from idk what country that have no stop signs or lights or roundabouts and somehow lots of people still manage to get through them
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.
There are quite a lot of videos of people ignoring roundabouts, and some of them even land on their wheels and keep going afterwards
I was in Aruba recently, and I discovered that they had entirely replaced their traffic lights with roundabouts. Easier to maintain and more efficient in the island's low-traffic regime.
Roundabouts are superior to other intersection types in nearly every case. Two lane roundabouts are a notable exception.
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
imho the only kind of acceptable 2-lane roundabout is a turbo-roundabout: https://en.wikipedia.org/wiki/Roundabout#Turbo_roundabouts
I was hoping that it was "404 not found"
My best friend is a highly experienced civil engineer, specialized in designing intersections. His take on roundabouts:
- They are adored by urban planners because they look nice and you can put a statue or fountain in the middle
- They reduce T-bone collisions
However:
- Small fender benders and sideswipes are much more frequent
- They use way more area
- 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).
- Finally, they're also (mostly) worse for cyclists and pedestrians.
Essentially, they have use cases, especially in small towns, and they're pretty, but they're usually not the right engineering solution.
It would be interesting to know your (friend's) country of origin.
I live in the US and roundabouts simply don't work.
Not much of America's traffic infrastructure works well. Every month, combined with poorly trained motorists, it contributes to another 9/11's worth of fatalities. The infrastructure you think works, kills enough people for a thirteenth month at the end of every year.
They have their downsides, but "It doesn't work in America" is more informative of American motorists than roundabouts
Yeah I regularly drive in France which has terrible drivers (road deaths way above EU average in France) but it's nowhere near as bad as the US.
The one thing people should ponder is this: Germany has less than 3x the number of road deaths (no matter how you count it: per 100 K people, per kilometer, etc.) than the US. And yet every time I'm in Germany I happily drive at 125 mph on the highway (including when I drive to Poland, where most autobahns near Dresde have no speed limit at all whatsoever). And at 125 mph, I'll get overtaken by some cars going proper fast.
So, what, 65 to 70 mph max speed limit vs unlimited speed and three times the deaths: what's the problem?
Note that I'm certainly not advocating for US (or France for that matter) highways without speed limits: drivers are way too bad.
Germany is somewhat an exception when it comes to good and safe driving though, I think they're all afraid the government will take Autobahn away from them if they drive too bad.
It's a huge difference passing through France, having near hit collisions every hour on the highway with distracted French families, arriving to start passing through Germany, and suddenly people actually use their blinkers, drive on the right side, seemingly everyone knows defensive driving, and no one is up in your ass if you're at the speed limit.
Love driving in Germany though, countries should look into how they managed to get the car culture they have. Maybe it helps the Germans invented the automobile and all that comes with that. Probably still there is lessons to be learned from them.
Legislators in the US won't cover the actual costs of road maintenance. Most cities issue long term bonds to finance road construction & repair, but in order to repay those bonds, those states & cities need to constantly grow.
Damage to roads is related to the third power of speed and the fourth power of axle weight.
Huh. You might want to look at how the residents of Carmel Indiana think about this.
https://www.carmel.in.gov/government/departments-services/en...
a city frequently ranked in the top 10 places in the US, also frequently ranked as one of the best cities in the US for cyclists.
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.
Roundabouts are perfect when youre confused, just go around and read all the signs 3 times, then select the exit! :)
How big was this roundabout when it took 25 minutes doing 3 victory laps in a roundabout?
You might want to petition your local government to put the signs of the exits before the roundabout, together with exit signs inside of the roundabout, helps a lot to see what exit you should take.
Alternatively, try a different map viewer, both Google Maps and Waze handles roundabouts excellently with zero issues, Apple Maps might still be too new to be useful for daily use.
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.
I think the main problem in England is that there is just too much traffic for too little road. I don't think there is a simple infrastructure solution to that problem.
For example I was going to point out that roundabout completely fail when one direction becomes nose to tail congested but when I thought about local examples, I'd rather take that over a set of traffic lights where it becomes near impossible to get out from one direction if the traffic keeps backing up onto the junction.
I think Jevons paradox basically guarantees this in both countries. The difference between the two countries (in my theory) is how much responsibility they're willing to place on the drivers. The UK requires much more driver effort for good reasons I suggest in another thread.
What's the problem with a roundabout on the interstate? Obviously it'd have to be huge to account for the speed, so people don't need to change speed too much, but given the right size, it'd work wonderfully.
Nothing depending on your perspective. Mine is a U.S. perspective and a disposition against. They slow things down and require more mental and physical capabilities than the U.S. approach. That’s not accidental or because U.S. people are dumber, it’s just a cultural difference between the countries in terms of driver expectations. I’ve proposed a rationale elsewhere.
Make the roundabout larger then, and you can keep just about the same speed. How can a roundabout take more mental and physical capabilities and slow you down less, than a stoplight on the interstate? That's very backwards, and not sure what roundabouts you've experienced, if that's the case.
There aren't stoplights on the interstate. That was the point I was making. (It got lost in the follow up.)
But to answer your question, roundabouts always require drivers approaching from all directions to slow down, lookout for cross traffic and assess other drivers' behavior. Stop lights have 2 modes that promise safe passage, and they can be set to prioritize routes.
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.
I agree with this, and I'll offer a rationale.
Because the US largely "grew up with cars", the economy was built around the expectation that folks can drive to work. The population density of the US reflects this, and mass transit just doesn't work in small/middle America. That means everyone needs to be able to drive. If you can't drive, you can't work. That isn't the case in the UK, and you'll notice a lot of these "driver beware" analysis is explained by the fact that driving in the UK is seen as a privilege whereas it is a right in the US. This sort of "mild chaos" is prohibitive for a lot of would-be UK drivers, and they just take the bus.
The UK has an over-reliance on roundabouts for junctions with motorways and large roads. They are also missing out on Turbo roundabouts, which are super cool and very common in the Netherlands.
The UK’s spiral roundabouts are the same as Dutch turbo roundabouts.
I don't want to celebrate UK roads too much. The majority of roundabout users in the UK are not indicating properly. Too many people are stopping at them when they have priority. Lanes are just a suggestion and using the correct lane is an invitation for someone to drive into the left of you.
In other areas: enough people don't know how to use a slip road that it becomes a problem to those who do. Likewise the flashing ambers of a pelican crossing. Lane discipline is much worse than on the continent, to the point you can see it creating traffic jams. Lots of people are driving big cars without the confidence needed to remain in their own lane.
There are millions of drivers who've never passed a theory test. We could do with more ruthlessness.
I feel like you're singling out UK drivers without much evidence here, I've driven lots across continental Europe, although mostly Spain<>France<>Germany<>Nordics, but in all countries people tend to not indicate properly, inside of roundabouts or outside of them. I'll admit to people in the Nordics being slightly better at signaling, but they make up by being so scared and non-confident in their driving that their hesitation causes near-accidents, rather than the opposite.
Still, all across the world the average driver seems to below what I imagined the average driver to be, before I started driving myself.
All of that is user error. The roads themselves might be in disrepair, but are otherwise well-designed.
It may be user error, but that doesn't mean roundabouts aren't a footgun. It only takes one driver who doesn't do everything correctly to cause problems. It's not much fun driving around in the correct lane, only for someone to pull alongside you to the left (equivalent of "right" in the US, of course!). I failed a driving test because someone cut across me on a roundabout.
"I failed a driving test because someone cut across me on a roundabout." That driver may have cut across you on that roundabout but that doesn't mean roundabouts are a footgun.
If a given tool tends to have a high amount of user error, odds are there's a problem with the tool
I mean, what you're trying to minimise is (frequency of misuse x consequences of misuse). signalised intersections target the frequency element, roundabouts target the consequences.
When comparing two interfaces and one allows a larger amount of user error that interface is inferior.
The point is roundabouts require more work to navigate correctly than a four way intersection with traffic lights. Thus drivers are more likely to navigate incorrectly.
Seeing a safety issue and ignoring all other considerations is an excellent example of the ‘overarching theory and imposed order’ I argued that Britain rejects in my first comment.
Yes, we're discussing how the users change the way traffic flows.
Not gonna lie, I know about the flashing ambers of the pelican crossing, but they are uncommon enough, whenever I see one, I spend several seconds wondering what is happening, until it clicks it's one of these crossings.
Try Spanish roundabouts. On the whole, poorly designed, implemented and regulated. On roundabouts with two or more lanes, laws favour those on the outside lane, so everyone takes the outside lane even if they are travelling 3/4 of the way round. As a result drivers who are in a position to take an exit, do not take that exit. In addition, indicators are not used by most drivers, or they simply leave their indicators on all the way round. In addition, it is not allowed to exit a roundabout from the inside lane even on to a two lane exit. In addition many roundabouts have three lanes to enter onto a two lane roundabout, or two into one, etc. No one knows the rules, or follows them, and no one seems to care, from the civil engineers right down to the end users. The only winners are repair shops.
In comparison, UK roundabouts are civilised examples of harmonious intellectual etiquette. Enjoy them.
[source] I learned to drive in Swindon, home of the Magic Roundabout.
If you complain about Spain, then go live and drive in Italy :)
I live in the UK, drive occasionally in Spain due to Spanish in-laws, and agree wholeheartedly. I didn't know about the "outside lane has priority" rule though. I'd noticed it happening, but just thought it was a national quirk rather than gaming the system.
American, in an area getting more roundabouts. The two most heartfelt criticisms of roundabouts I've heard are:
- I have to pay attention every time I go through one. (Vs. having your mind elsewhere works fine with traffic lights? That might explain some of those T-bone crashes.)
- Certain multi-roundabout intersections are "because the Road Dept. hates us" horrors to drive through. Most-often cited - https://www.google.com/maps/@42.5058488,-83.758072,18z?entry...
From my PoV, roundabouts are generally a good thing. Mostly because local engineering standards for traffic lights are wretchedly low - so I can get where I'm going far faster through roundabouts.
As a European, that roundabout intersection looks fine? It might be slightly annoying to have to use all three roundabouts if you're exiting the highway northbound and want to take the southbound local road, but with the amount of exits there I can't imagine a junction would be better.
"They work perfectly fine."
The fact that you mention light-controlled roundabouts highlights that they do not, actually, "work perfectly fine".
Roundabouts are a practical example of the tyranny of the majority; minor traffic flows suffer against major. The centre of Salisbury is a perfect example, constantly gridlocked at two roundabouts except at odd hours on a Sunday.
Adding traffic lights to 'fix' this problem then leads to tailbacks on the major routes and congestion on the roundabout, such that the timing sequence for the minor routes are subsequently reduced, returning to the original problem.
Roundabouts, in the plurality, are used as a lazy 'solution' to at-grade traffic crossing, which the road designers themselves presumably don't have to suffer. They also cause pollution from brake dust from slowing and exhaust fumes from accelerating.
I don't think anyone is claiming that roundabouts work in every and all situations: design handbooks often say they're good 'up to X vehicles per hour/day'.[1] But that does not mean they do not work, or not useful, for <X.
Intersections are an engineering problem, and there is a hardly ever an engineering solution that works everywhere and always. There is usually a spectrum of solutions for the various situations that are faced.
[1] https://www.fhwa.dot.gov/publications/research/safety/00067/... § 1.6.1, 3.3.1
Well we have very different experiences driving to, through, and around Salisbury. There's traffic, and it can get bad, but it isn't as bad as you say.
The council and national highways are working on it, but the problem is not one of roundabouts - its one of increases in traffic and lack of capability to make the roads bigger and/or build a bypass. Unless we're willing to knock down a load of housing and cultural sites we're stuck with something around or slightly more than the road capacity we have.
I have no idea what this means but I love it!
In very heavy traffic conditions I suspect that roundabouts can gridlock all directions in a worse way than a standard intersection with a yellow box because everyone tries to enter the roundabout then they get stuck in it, and then the whole traffic is brought to a halt, including directions that should be unaffected. This happens very often where I live.
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".
A place where traffic slows down, without actually stopping, and becomes congested with no time/space gaps between vehicles, is worse for pedestrians.
No it isn't unless all driver all break the law and don't stop for waiting pedestrians.
That's a thing that happens.
But then, how come you blame this on the existence of roundabouts and not on the lawlessness of drivers?
Because driver compliance with red traffic lights is far, far higher than compliance with pedestrian right-of-way rules.
And the reason is obvious: when the driver runs the law of the red light, they run into a law of physics (cross traffic).
The traffic has to yield to pedestrians when entering and exiting a roundabout, period.
Not in UK.
However there are often pedestrian crossings across the roads or the volume is low enough pedestrians can easily cross. A local roundabout got busy enough we had crossing added less than 10 years ago and the biggest road there was a minor B road.
I am a pedestrian due to sight issues and have found very few places where it is difficult to cross when needed.
This is true if you can alter the properties of the physically existent universe, else it is not true, and, indeed, drivers do not even slow down largely because they feel frustrated when traveling along a road with a 45 MPH speed limit at an average speed of 20 MPH.
Why? This feels like it's assuming pedestrians share the street with vehicles, but besides the US and some other places, don't most "modern" countries have separate pavements/streets for pedestrians? Besides in the country-side, vehicles and pedestrians don't generally share the road in populated areas here in Spain. For crossing roads outside cities, building a pedestrian tunnel below or a bridge above seems to preferred here, except in the cases where it isn't possible, and in cities obviously.
In my city in Norway, at least, there is never a traffic pattern where it's not either:
* a small roundabout with really clear pedestrian right of way marked
* a pedestrian path that takes you over or under the road instead of crossing it
It's great!
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Right, you're talking about "traffic participant", are you including pedestrians or not? Because as I said, in many places, "vehicles" and "pedestrians" are well-separated and don't impact/affect each other, so not sure what cluster-fuck could be created there. Seems less of a cluster-fuck than relying on cross-walks and stop-lights?
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Posting like this will get you banned here. If you'd please review the site rules and stick to them, we'd appreciate it:
https://news.ycombinator.com/newsguidelines.html
There used to be an epidemic of cars striking and killing pedestrians. The advertising industry (hired by the auto industry) came up with the new imaginary crime called "jaywalking". This diverted attention from the killers and onto the victims. Just one more version of the victim blaming that derives from the Just World Hypothesis.
https://en.wikipedia.org/wiki/Just-world_fallacy
Some data seems to conflict with this:
* https://www.tac-atc.ca/wp-content/uploads/weber.pdf
* https://mdl.mndot.gov/items/202336
OK, so "worse for pedestrians" boils down to a statistic about body hits. If you are not struck, you are not having a worse pedestrian experience. My bad!
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.
Platoons of cars with space in between allow for pedestrians and vehicles to cross the road, downstream.
Nothing worse to have upstream of where you are trying to enter a road, or cross it, than a busy four way stop, with cars coming out of it at regular intervals, without sufficient time/space in between.
As a bicyclist and pedestrian (in Denmark) what is it that’s worse about roundabouts for me? I think they work really well.
I think to an American, a roundabout is this thing that only works for cars and don't take pedestrians or bicyclists into account, with no paths or crosswalks or anything, so hence "Worse for pedestrians". I don't blame them, both roundabouts and care for pedestrians seems uncommon over there, so of course their experience will point towards roundabouts being worse overall.
(UK experience) If you're trying to cross the road leading onto one, it's much harder to tell if a vehicle is going to hit you at speed. I often observe people turning quickly, without indicating, and had I chosen to cross at that time, there would have been some kind of accident. Junctions tend to not have this problem since cars turning out of them are usually going much slower.
I will say 2 lanes roundabouts as a cyclist are a little intimidating when you need to take the inside lane. Drivers are not looking for cyclists the way they look for cars or will rush to get ahead of you or just try to bully you out of the way by entering the roundabout across you illegally and daring you to take the right of way. At particularly busy examples I will dismount and take the pedestrian crossing.
Junctions have their own problems though: Usually drivers will not permit a cyclist to merge in front of them while traffic is not stopped, which means if the stream of traffic is continuous you need to plan your lane change when traffic is stopped by lights.
As a pedestrian, roundabouts with islands (aka all roundabouts here) are vastly superior.
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).
I think it's fine with lots of traffic in a roundabout, but it has to be somewhat balanced.
For example, we have a roundabout that sits on a relatively popular road, with one exit/entry that leads to a bigger highway. During rush hour, there is heavy traffic, from from/to every one of the three points, so traffic naturally divides, as cars turn off.
However, when there is no rush hour, the highway exit/entry isn't used, so cars mostly just pass through the roundabout, and everything still works, as the two entries/exits are still balanced.
Issues would arise if it's only one entry/exit being used, as then it'd always block the two other entries from being used properly, but seems that never happens, so seems to me it's proper and works well, regardless of the traffic being heavy.
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.
I don't understand the argument? Seems like you're saying that not having to handle a gear change makes roundabouts better, but that applies to both your manual technique and automatic, so I don't see how Europe would be different from NA?
Also, I'm not a particularly frequent/experienced driver but 4th gear at 30kmh on a roundabout doesn't seem very safe, it does not leave you much control to react to something unexpected (some car coming up that you didn't see, a car who changed their mind last minute about exiting, a car changing lane poorly...). Being able to decelerate or accelerate quickly is pretty important on a roundabout. Not such a big deal on a very big roundabout with excellent visibility where there's no-one, but that's pretty rare in europe at least.
Rather, what I don't understand is the original argument that roundabouts are bad because the busy direction of traffic has to slow down and gear down unconditionally, whether or not the rare cross traffic is present, so it is then better to have a traffic light there.
The "you need power to accelerate out of danger" is a motorcycle argument (and a pretty flimsy one); in a car, you are not gas-pedaling your way out of anything. Your emergency control devices are brakes and steering, that's it. There are moves that powerful acceleration lets you get away with, and they are all reckless, and often built on the assumption that only you have that acceleration. People are now using their high-torque EVs like this. You will never be in a collision close call caused by someone or something doing something unexpected, where the reaction of stepping on the accelerator is the action that saved the day. Can't deny that it could help run from a tsunami wave or fire or something.
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.
Not a civil engineer but as far as I know, the space is part of the point. If you keep the roads straight but just draw a circle in the middle, you don't have a roundabout. It only works properly if the drivers have to curve in and out of it.
You could keep the same space I guess by pinching the roads tighter near the entries/exits but I don't think anyone is talking about that.
The UK has mini roundabouts, which are just a painted white circle on the road: https://upload.wikimedia.org/wikipedia/commons/b/b0/Mini-rou...
Drivers treat them as a normal roundabout by giving way to traffic on the right.
I contest that drivers always treat it the same. They often go through the circle/cut th corner when there is low traffic, and I know at least one mini roundabout where traffic is way less frequent in one direction and the other direction is treated as the "main road" without slowing down.
I mostly like them though.
If it's physically possible to "skip the roundabout", if it's just a drawing rather than hard barriers, people here (Spain) will just skip it straight up, unless there is a ton of traffic. I think lots of these driving rules and infrastructure has to take local culture into account, as it differs from "We follow laws like our collective lives depend on it" to "We see laws more like suggestions" depending on the country.
That approach fall down flat on nontrivial traffic amounts. Also it requires an actual hindrance in the middle to enforce compliance, and then bigger vehicles won't be able to turn left.
Drive a school bus through there. Let me know how that goes.
In Sweden they have these huge roundabouts in the countryside. Very large diameter and gentle curves. You can maintain your speed. Awesome. Saves energy too. I assume there's a huge amount of tried and tested traffic innovation that could be directly just copied.
In Spain we have these two, sometimes right outside metropolitan areas, that see a lot of daily traffic, especially around rush hour. They're naturally balancers, if you plan them correctly, makes a ton of sense to default to roundabouts instead of stoplights.
Especially nice for us who plan our car trips based on when there will be the least public traffic out there, as roundabouts don't force you to stop when there is no traffic, and you can essentially keep the same speed with these large roundabouts.
Do you have any data on this? Everything I've ever read about them points to exactly the opposite conclusion. They actually reduce accidents and by a significant margin.
My only guess would be that you are referring to the US, where people are not used to roundabouts and yielding without a STOP sign.
For cyclists, this is mostly true IMO (depending on implementation), but for pedestrians roudabouts are way better than traffic lights. In the absence of lights, pedestrians have right of way on crossing, so no waiting time, and physically slowed traffic make it safer.
This is ignorant texbook thinking.
As a pedestrian it's far easier to safely time a light, even one without a cross signal, than it is to cross through the un-broken streams of traffic that are entering/exiting a roundabout. You basically have to cross a ways back from the roundabout where the traffic is more like "just crossing a normal road". Which sucks if it's 4-lanes or really busy or fast or there's no sidewalk provision for that (like in the case of roundabouts at highway ramps) and is just a lot more walking to begin with.
For roundabouts that wouldn't be deserving of a light (i.e. the ones replacing 2/4way stops) it's a lateral move.
The point is that traffic streams are not unbroken: when there is a crosswalk and cars are obliged to stop in front of it in the presecence of a pedestrian, then the flow is broken.
Being obliged to stop and actually stopping are not the same.
In the real world, drivers frequently do not stop in the presence of pedestrians.
Just blundering up to crosswalks because "they have to stop, hurr durr it's the law <foams at mouth>" results in a substantially more hazardous pedestrian (and driver) experience than timing your approach and using your body language so that the drivers know what you're gonna do and can take action to hedge against it.
Indeed, this is so, so true.
Especially with heavy traffic, the traffic all slows down, a lot, from the section before the roundabout. Everyone is always in a hurry, so likely 10-25 MPH over the recommended speed (not the speed limit) for the roundabout, and all of them are at a 6 foot following distance.
You are playing with death to step into that. It's no joke. You end up effectively waiting for the upstream light to turn red so traffic can clear and you can cross.
The only solution I've thought of is to put a large grocery cart full of paint buckets at the roundabout for pedestrians to push into the crosswalk without risking their own lives.
I mean, it depends on your standards for roundabout. We didn't put highways through town centres so largely highway ramps and pedestrians are mutually exclusive scenarios here. Where pedestrian crossings exist, there's usually (a) an island and (b) 2 lanes prior to the island, splitting to 4 lanes either where the traffic is already slowed or past the island, which makes it much more pleasant than crossing at an equivalent junction. Also as a driver, it means you've cleared the pedestrian area before you have to consider/deal with the cross direction drivers as there's a small waiting area post-pedestrian-crossing/pre-roundabout.
If you're stuck because you already have a highway in your urban core and need pedestrians to safely cross the highway, then you are pretty much limited to overpasses and underpasses.
You know that's like, the entire point of roundabouts: force traffic to slow down.
Another pro: they can easily support more than 4 connections
another con: If only one of the exits gets backed up, it clogs the traffic circle and causes every connecting road to back up.
Roundabout cyclist and pedestrian safety is a solved problem, in the Netherlands of course.
Depends on the driving culture and familiarity with roundabouts for sure. Moved from the US to a city in Norway with almost exclusively roundabouts, and it's _so much nicer_. Even in the edge cases, I have never once found myself wanting a traffic light.
Simple intersections can have very small roundabouts, and bigger ones you can connect roads from so many weird directions and have traffic flow well that I would never want to return some of the intersections I experienced in the US.
The "use more area" needs to be considered in the sense that, designed properly, they eliminate left turn lanes and "suicide lanes" in the center of the road.
Instead, with proper design, you make this "left turn" by going to the next roundabout, going around to follow the road the opposite direction, and then make a right turn.
It's also only true when compared against a no-frills intersection. A two-lane roundabout has better overall throughput than a two-lane intersection with traffic lights. To increase throughput, they usually add turn lanes to avoid cars having to stop in the through lanes -- but the turn lanes require more road surface than the roundabout would have.
The replies to your comment would be a lot funnier if I didn't share a country with some of these people.
You're not gonna "driving culture" your way around a 10:1 volume difference and only a fool would act like you could.
And this is coming from someone who's a big fan of roundabouts (and 4-way stops) on the basis that bad drivers have a worse time at them.
That would generate stronger agreement if the bad drivers’ struggles mostly affected them. Instead, their chaos radiates outward significantly onto those who know how to drive.
But collisions overall are down, and severe crashes down 80%:
* https://tirf.ca/blog/fact-vs-fiction-roundabouts/
While it would slightly defeat the purpose in some ways, roundabouts with traffic lights are a thing:
* https://www.traindrivinginstructor.co.uk/roundabouts-with-tr...
So if one way has heavier traffic (at times), things could be signalized to allow (e.g.) that one direction primarily some of the time and the other three directions the rest.
Some data seems to conflict with this:
* https://www.tac-atc.ca/wp-content/uploads/weber.pdf
* https://mdl.mndot.gov/items/202336
Roundabouts are also a torment if you have car sickness.
My main two cons with roundabouts are that one, when you have those residential streets where basically every intersection is a roundabout so you get many of them in a quick sequence when you’re going straight all that centripetal force is annoying to deal with.
And the second thing is when you have very large roundabouts, there’s always a bit of chaos involved between shifting lanes from the innermost lane towards the outermost lane because I’ve noticed people don’t enter the roundabout on the right lane, so there’s always a little bit of chaos during the crossover.
The key disadvantage of a roundabout is that it takes up more space and is harder to setup than plopping down a couple of stop signs.
They are awesome otherwise, I do like them better for low traffic intersections though because I don't have to stop and think about if the next car is going to yield or not.
Only large roundabouts take space. Small roundabouts can easily be retrofitted into small, unguarded residential neighborhood intersections without clawing back any sidewalk corners. They just plop a curbed-off circle in the middle of the intersection, leaving a narrow passage around it. Now a car going straight has to swerve into a crosswalk that is going in the same direction. Massive win!
I think here in China we are not super fan of roundabouts. But we got a 4-lane roundabout with traffic lights [1] and a roundabout on elevated roads with traffic lights. [2]
[1] https://maps.app.goo.gl/rY6AH8nUEKvRuk1LA
[2] https://maps.app.goo.gl/Wea6Wt5FwHgKmG4C9
Reminder that technically a 4-way stop is the smallest possible roundabout.
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.
Roundabouts often have stop signs, usually when you really need to slow traffic down(lots of pedestrian use)
In the UK I have seen 3 way roundabouts
In the highway code see rule 190 for two threeway roundabouts stuck together. https://highwaycode.org.uk/roundabouts/
Wikipedia shows a few e.g.
https://commons.wikimedia.org/wiki/File:Germany,_Sachsen-Anh...
https://commons.wikimedia.org/wiki/File:Waterloo,_Ontario,_m...
Roundabouts are the Segway of civil engineering. In theory, a game changing transport innovation. In practice, just a little too mismatched with everyday aesthetics to properly fit in. Dorky and annoying for pedestrians too!
Good old traffic lights have a much better feature of being able to control traffic to allow for pedestrians, give cyclists a head start, give smaller side roads a look in at busy junctions, and giving a platform for traffic monitoring.
I feel like the author would appreciate Milton Keynes, which is an entire city of 180 roundabouts on a grid system:
https://lostcolonials.wordpress.com/2015/09/20/milton-keynes...
Fun for drifting late at night. Like a chav version of tōge from Initial D.
Appreciate indeed. Thanks for the reference
It's so funny seeing most of the comments, plus the original article, implying that roundabouts are always better or always worse than traffic signals. As someone who used to be a Transportation Engineering professor, they have a time and place where they outperform traffic signals but it's definitely not everywhere. It is known and there are many traffic simulation software tools that will give you a pretty good indication of what will happen if you put a roundabout here or a traffic signal there.
This thread reminds me of when my libertarian friend was explaining to me how traffic shows how everything can work well when everyone acts in their own self interest. Well, sure, except for all the traffic laws, the difference between User and System Optimal that traffic engineers spend much of their lives trying to bridge, and, you know, the fact that it took an enormous effort by government to build smooth roads and put up signs everywhere. Sigh. I'm not saying Transportation Engineering is the most important, innovative field, but funny things happen when not transportation engineers talk about transportation systems.
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.
Love this.
Likewise "free markets" which work great when embedded in a system of laws and regulations. Or more critically, in a high-trust system where people keep their word because that's what matters.
But not sure how many people are in favor of the more unregulated black markets, where contracts are enforced by rule of violence instead of rule of law.
As if we've forgotten Hobbes, and the horrors he lived through which informed his philosophy.
One additional benefit (or at least an unproven, theoretical benefit): https://www.youtube.com/watch?v=qdbJJ8UhM1I
Maybe, living in France where maybe half the roundabouts of the world exist, I have been exposed to too much beauty.
But mostly I see roundabouts as one of the most depressing, ugly and environmentally-destructive gimmicks of 20th century car culture.
Did anyone study the fuel efficiency of a roundabout vs. traffic light?
I expect it to be a lot worse.
You're missing the variations where you have stop lights to go into the roundabout or the even worse variant, roundabouts that are large enough to have 3-4 zones of stoplights inside of the roundabout itself!
I'll take a roundabout any time of the day, but then I mostly to drive out in the public when the traffic is the least, so any stop lights tend to be more annoying that useful.
Streetcraft on Youtube compared 2 similar routes, one with roundabouts and one with traffic lights. They found roundabouts to be quicker and more fuel efficient: https://www.youtube.com/watch?v=012fMI3TdRo
Mythbusters did a test of roundabouts vs fourway intersections (no lights), many years ago.
Their conclusion i believe was they were about the same in pretty much all regards.
It was highly synthetic, people driving around a small course with roundabouts or fourway intersections, continuously for an hour or something.
Surprised Carmel, Indiana hasn’t been mentioned in article or comments. They replaced almost every single stoplight and stop sign intersection in the town with roundabouts. Think the number of roundabouts in the town is in the hundreds
One thing the US could do to make traffic lights a lot safer is copy eg France and only show the lights on the near side of the intersection.
In France, if you move up too far, you can no longer see what color the light is — consequently everyone waits back where they should.
In the US, you can edge out into the traffic and still see your light.
Not sure this will stop people. In Spain we have the same, the stop lights go before the pedestrian zebra thing, yet still some people think you're supposed to stop on top of the zebras, beyond the stoplight, then they wait for someone behind them to blink. No, makes no sense to me either.
You can tell which countries are pros at roundabouts based on the number of direction arrows in them.
Obligatory link to the clip where a TV interview about a dangerous roundabout catches an accident on film. There's English captions.
https://www.youtube.com/watch?v=pBtrEZpa6OQ&pp=ygUQcm9uZGVsb...
Yes, roundabouts are good, but there's things to consider.
I enjoyed driving around Lanzarote in the Canary Islands because you'd occasionally see roundabouts with wind-driven sculptures by César Manrique - e.g. https://maps.app.goo.gl/mzK8by7shYJ2yvYC9 - an artist who lived there.
His house, built into the volcanic rock, was beautiful too: https://en.wikipedia.org/wiki/C%C3%A9sar_Manrique#/media/Fil...
I'm old enough to be "triggered" by the word "Roundabout" to have this "Yes" song to start playing in my head:
https://www.youtube.com/watch?v=QOrrNM4md8c
I wonder, does the song have more fans today because of Jojo, or because of fans from when Yes were in their prime?
These don't work in the U.S. as everyone fantasizes they do.
An important note: in the U.S., the vast majority of jurisdictions permit making a right turn on a red light, and some, including the state of Oregon, permit making a left turn onto a one way road from a red light. In high congestion areas, such as here in Las Vegas Valley, many drivers will not fill a right lane at a red light when they are not turning right as a courtesy to those needing to turn right at the intersection.
During commute hours, everyone disobeys all laws to get home or get to work. When there are regularly spaced roundabouts on a long stretch of road, drivers get exceptionally impatient and will drive at the performance limits of the vehicles, late-braking like they are F1 drivers. This ends up grouping all of the drivers into a very solid wolf pack who will not stop for anyone and will speed through the roundabout, making it impossible for pedestrians and drivers other onramps to enter the roundabout.
The vast majority of drivers do not know how to use the roundabout, as is evidenced when they enter from the left lane of a two-lane road and use the exit lane that is only marked for use from the right lane. Americans who know how to use the roundabout respond to this by habitually stopping at the roundabout entrance when they see a car in any lane entering the roundabout at high speed, which is most vehicles. Then the drivers behind the stopped vehicle think the stopped vehicle is driven by someone who doesn't know how to drive on a roundabout and begin honking incessantly or attempting to illegally pass the stopped driver.
Henderson, Nevada provides many such examples of this. Most interesting to me is that parts of the town have nearly identical roads that are served by either only traffic signals or only roundabouts. My experience is that the roads with traffic signals have far fewer issues than the roads with roundabouts.