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.
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.
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.
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.
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.
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.
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.
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.
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 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".
> 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.
> 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?
Surely this is a joke or just a flimsy pretext to imply that murka bad or whatever.
Even with a fully paved and sidewalked roundabout (or intersection of any other type) the more of a clusterfuck it is the less time and attention any given traffic participant has to give any other traffic participant is and this is where you get all the stupid "idiots trying to pass each other in a hallway" type misunderstandings and whatnot. It's just better for everyone if things aren't a clusterfuck.
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?
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.
> 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.
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.
> 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.
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.
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 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.
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.
> 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.
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.
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.
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.
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
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.
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.
> Guess what works better and barely has any traffic issues at all.
The one that where mass transit works better.
But yeah, a city still needs cars, and roundabouts are still unbeatable in low-traffic crossings. But they are not the most impacting change a city can make.
As a bicyclist I hate them, at least the smaller ones. Because they slow me down, can't take them with 40 to 50 kph, need to slow down to 30. But that was the intent, yes?
However, crossings with traffic lights I can take at any speed I'm able to, when they are green for me, and I don't need to turn. Or if I can oversee them from afar, and they are empty, and I can give a shit about 'lights'.
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.
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 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.
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.
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.
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
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 replaced a intersection near me that would get backed up very badly during rush hour with a roundabout that has a much higher capacity and never seems to get backed up.
Nowadays, depending on your state, they're being built in almost every new intersection that would call for one. And the worst existing intersections converted to them. It's happening and will only speed up.
They’re being used often in new construction areas. It’s just not likely that they’ll be retrofitted to existing areas due to needing more space than regular intersections.
They are everywhere in the areas around me now. I had a similar sentiment at one time and now they seem pretty common.
I think roundabouts work fantastically well in some places but in others they are unnecessary and in others don't work as well as alternatives. Maybe that's obvious but every so often I feel like they are overapplied — probably because of what you're mentioning, along with the fact they were underapplied in other areas in the past. I've come to like them usually but sometimes it feels like the civil engineers were having too much fun at the cost of practicality.
> 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 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]
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 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.
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.
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.
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.
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- 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.
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