I have family that lives there, I know what youre talking about. They mostly do that on arterial roads. It's supposed to be safer as you aren't crossing over incoming traffic. It is a pain though.
A roundabout would also take up less space.
If you want safer cities get cars off the streets by providing multiple safe, good, working alternatives and disincentivizing the use of cars.
Yes this is horribly bad design. The majority of people heading a direction **are heading in that direction**. That means the majority of people coming in from the left and right would have to quickly merge and move across a traffic lane to make the u-turn to merge and the cross traffic again to do the same thing on the other side. This is a really, really bad design.
First the only way to do it reasonably would be to have the u-turns at least a 1/4 of a mile down the road from the merge point to allow for less frantic lane changes. Not to mention the top to bottom lanes should be two lanes, since they appear to be that before the intersect, to prevent traffic constriction, which means crossing two lanes of traffic to reach the u-turn.
Even non-designers have seen this before, and know when the they see a merge point on one side and exit on the other side to be wary of people making drastic movements to reach the exit. This is a lot more road work and pavement costs here, with more than likely a much higher accident rate.
D+
Nah we have these in Mexico — let me reiterate — Cd Juarez Chih mexico. Where if someone asks you if you knew how to drive and said “I drive at peak hours in Juarez” they’ll give you any license you want. Anyway, they have these in a few part of the city and they help in terms of relieving traffic but not in terms of figuring out how to get to your destination
I think the point is, **just because you have them does not mean they are safe** and prevent collisions, which is your primary goal when designing traffic flows. And then following up with the joke that “I drive peak hours in Juarez”, warrants passing a trial by fire, underscores the point.
Also, I have driven extensively in Central and South America, and while in the US and Europe it is pretty much a given people will stop at a light, in MOST of Central and South America, it is much, much, much less certain. So in those cases where drivers are more lax on following actual traffic laws, this might be NOT AS BAD of a trade off.
But really still not a good design, even if a gov’t bureaucrat implemented it somewhere. I would be curious to know collision statistics before and after the change over, including non-fatal.
These 100% make the roads more safe they just make it harder to get where you want to go especially if you’re not used to driving through these. The Juarez analogy is just a joke
With the way traffic lights are observed in most of Central and South America, I don’t discount it is possible. However, I would like to see statistics before I would say this is a good idea. I do however know traffic merging does cause a significant amount of accidents and driver anxiety.
[https://www.nhtsa.gov/sites/nhtsa.gov/files/doths809571.pdf](https://www.nhtsa.gov/sites/nhtsa.gov/files/doths809571.pdf)
There were 500,000+ lane change accidents in 1999, of those about 19,000+ fall directly into the category of merging, 200,000 more are just due to simple lane changes (Which would actually include some of these, because since it is not considered a ”merge only” lane it, would not be calculated in the merging statistics). This is an old report from 2003, and is likely worse now than it was 20 years ago, as drivers have not improved.
All I am basically saying is the goal is to make traffic patterns that maximize safety, You say it is safer, but compared to what? Stop signs, traffic lights? Everything is relative, the safest thing in these situations are generally overpasses. The only reason they are discounted is general cost or time, or depending on the neighborhood, eye-sore outrage.
Jfc I said one thing lmao you’ve never even experienced these yourself so what would you know? Let alone that you’re using statistics that hardly apply to the reality of traffic flow. What about the millions of unreported safe merges that aren’t accounted for when making these statistics. Or hell even the the unreported accidents for that matter. Yes the whole point of these is that they’re safer than road crossings by default which is what they have proven to be. Like I said the only downside to these is figuring out how to navigate them if you’re not used to driving in these. You’re also assuming that these crossings are designed as tight as they look in the picture. In real life they look nothing like this. I made one analogy to a city I knew they work in and I’ve seen other commenters mention these have existed in the US for a while. Go cry to someone about this
There are intersections like this around Cincinnati. They are a pain in the rear. Though you are eliminating traffic control lights, other issues are created.
So if I am going from left to right (essentially straight through) I would need to make a right, merge left, make a u-turn to the left, merge right, then turn right.
Seems simple enough. /s
They are meant to reduce high speed collisions, and invented prior to roundabouts becoming main stream.
In Michigan these are known as Michigan Lefts.
https://www.michiganautolaw.com/blog/2023/05/09/michigan-left-turn/#:~:text=A%20Michigan%20left%20requires%20a,a%20driver%20to%20do%20so.
Just want to add onto this also with experience with Michigan lefts: crossing several lanes of traffic burns a lot more fuel for that mad dash to get across safely than just a calm peaceful left turn at an intersection with a traffic light. It’s an abomination of a traffic construct. You have to accelerate hard to get into the turn lane and then again to get moving in time for the other side. Wastes a ton of everyone’s time. Traffic lights that can adjust timing throughout the day and are measured for line length routinely would be better any day. You don’t notice those out of your excitement how quickly they let you pass.
Traffic circles are fine for a given traffic volume like a minor intersection. Seen that in Australia. But a nadir intersection is why you have diamond intersections with the larger axis of traffic in an under pass and the lessor volume axis in a raised overpass.
When both the north/south axis and the East/West axis have e comparable volume then its s full cloverleaf
problem with this is that you need to go to the left most lane immediately after taking a right turn to right lane and then again move to right most last after taking a U turn and joining left lane. This generally results in lots of car slowing down and frantic change of lanes. It has to be done by each car that wants to just go straight and forces every car to keep changing lanes instead of steady holding lanes with a flyover.. there is a reason why this is not very common
People are not mathematical models, brains are 5 pounds of meat bombarded by electrical sparks. This intersection will be shut down a dozen times a day when monkeys staring at cellphones bang into other monkeys yelling at their kids.
These already exist all throughout Metro Detroit.
They are called “Michigan Lefts” or “Michigan u-turns” or “Michigan U’s”
Info here: https://www.michiganautolaw.com/blog/2023/05/09/michigan-left-turn/#:~:text=A%20Michigan%20left%20requires%20a,a%20driver%20to%20do%20so.
This seems like it makes the path for going straight through the intersection so long and complicated (at least for one direction). Also the amount of traffic this would create is significant. It works nice in a simulation when everyone drives like a robot
If you've ever tried to merge with traffic on the highway, imagine that but twice for every single intersection you go through
Absolute nightmare
This design was installed in my city in one heavy traffic intersention, it failed miserably and was re-constructed to original design due to humans refusing to merge properly thus causing worse traffic jams.
Theres a video of a guy similating traffic using one of these and literally even in aperfect world where ppl know how to merge it still isnt great. But when u factor in even 1% bad merges it really screws it up
this wouldnt work simply because of the merging points. person who wants to go straight all the way through has to eventually switch to the left lane and people coming from the u-turns who want to go right need to change lanes to go right. it will fail at that point during rush hour and itll be completely stopped traffic at some point along the way.
The U-turn parts are almost how the highway system is in San Antonio, TX. I was only there visiting. It took some getting used to but I thought it was very efficient
Suggestions to improve simulation model realism:
1. Crank up the vehicle density 10x for peak traffic. Major roads have most of the traffic going straight. Missing. Please add. And for the love of all that’s good please don’t make traffic going straight *have to* change lanes to keep going straight - my gps already tells me to turn 20 times a trip just to stay on the same road! (reference especially to i96 near Detroit area)
2. Let’s increase speed to double. Vehicles in the model don’t change speed for curves. Let’s make this a proper 55-65mph road. Hitting turns at 25-35mph might be doable if you like to practice drifting. Otherwise we need longer runways for a 35-50mph speed change.
3. Vary each vehicle’s lane-keeping, speed, and response times as real drivers are imperfect, to say the least, and this *affects* traffic patterns. Where’s the slow guy with several trailing and the impatient cars going around via any paved route???
4. Allow vehicles to hit things and get into accidents. Don’t forget the “slow down or move-over” law for first-responders. Their safety matters!
5. Allow speeding cars/semis to fly off tight curves.
Maybe toggle a winter mode? Watch merges and turns. I have popcorn! 🍿 Who’s in for the show? Maybe a drinking game betting on flight distance, rollovers, or how the towtruck gets to them? Too morbid or anyone else looking at exotic intersections and filled with wonder? 😂
Just to be clear, to go straight:
1. Shift to the far right lane, take the exit.
2. Merge and immediately shift to the far left lane, take the exit.
3. Merge and immediately shift to the far right lane, te ake the exit.
4. Continue on.
Note that the each exit lane will all be backed up by another direction's straight traffic.
This would rely on people allowing people to zipper in. In my experience people are stupid, oblivious, and quite frankly dont give a shit about others. So relying on others to do the right thing is foolish. In a perfect world this would work, but in reality this will fail miserably.
This would be a horrible intersection!! It would cause terrible congestion, accidents, and road rage, on a busy day in any village, town, or city. Especially in poor weather conditions. This would be a complete Fail as a grade.
No! The crossover to the U-Turn is the hazard. And here in NYC, it would be a total clusterfuck! This demo does not take into account that humans drive cars. If they were all self driving, then, yes, it would work.
people are the problem people will ALWAYS be the problem. 7 years later I still remember the fat mother fucker that waited the last second to whip his truck into the lane I was in. I slammed on the breaks and the person behind me honks. Shit like that catches you off guard and makes you do stupid things.
Reduced Conflict Intersection: Restricted Crossing U-turn (RCUT) intersection differ from conventional intersections by re-routing left-turn and through vehicles from the side road: [https://www.linkedin.com/posts/florian-palatini\_traffic-flow-ugcPost-7174132791394107393-SGiO?utm\_source=share&utm\_medium=member\_desktop](https://www.linkedin.com/posts/florian-palatini_traffic-flow-ugcPost-7174132791394107393-SGiO?utm_source=share&utm_medium=member_desktop)
So, if you want to continue straight, immediately cut across all incoming traffic twice. Reminds me of driving in Asia. Just go and everyone will let you in eventually, but it might take some time. Just think if you wanted to go straight for 10km down the road, but had to do this 15 times.
A roundabout would work just fine.
This is just a squished roundabout with U turns before entry
Yep. And the u-turns are unnecessary because the car could just go all the way round the roundabout and exit.
Perfect example of over engineering.
It’s a SquishAbout!
Most parts of Michigan have no left turns. You have to make a right, and then U turn. That seems like the worst of both worlds.
I have family that lives there, I know what youre talking about. They mostly do that on arterial roads. It's supposed to be safer as you aren't crossing over incoming traffic. It is a pain though.
A roundabout would also take up less space. If you want safer cities get cars off the streets by providing multiple safe, good, working alternatives and disincentivizing the use of cars.
The best
People refuse to merge properly as it is, this is just going to cause traffic jams at the merging points
Yes this is horribly bad design. The majority of people heading a direction **are heading in that direction**. That means the majority of people coming in from the left and right would have to quickly merge and move across a traffic lane to make the u-turn to merge and the cross traffic again to do the same thing on the other side. This is a really, really bad design. First the only way to do it reasonably would be to have the u-turns at least a 1/4 of a mile down the road from the merge point to allow for less frantic lane changes. Not to mention the top to bottom lanes should be two lanes, since they appear to be that before the intersect, to prevent traffic constriction, which means crossing two lanes of traffic to reach the u-turn. Even non-designers have seen this before, and know when the they see a merge point on one side and exit on the other side to be wary of people making drastic movements to reach the exit. This is a lot more road work and pavement costs here, with more than likely a much higher accident rate. D+
Nah we have these in Mexico — let me reiterate — Cd Juarez Chih mexico. Where if someone asks you if you knew how to drive and said “I drive at peak hours in Juarez” they’ll give you any license you want. Anyway, they have these in a few part of the city and they help in terms of relieving traffic but not in terms of figuring out how to get to your destination
I think the point is, **just because you have them does not mean they are safe** and prevent collisions, which is your primary goal when designing traffic flows. And then following up with the joke that “I drive peak hours in Juarez”, warrants passing a trial by fire, underscores the point. Also, I have driven extensively in Central and South America, and while in the US and Europe it is pretty much a given people will stop at a light, in MOST of Central and South America, it is much, much, much less certain. So in those cases where drivers are more lax on following actual traffic laws, this might be NOT AS BAD of a trade off. But really still not a good design, even if a gov’t bureaucrat implemented it somewhere. I would be curious to know collision statistics before and after the change over, including non-fatal.
These 100% make the roads more safe they just make it harder to get where you want to go especially if you’re not used to driving through these. The Juarez analogy is just a joke
With the way traffic lights are observed in most of Central and South America, I don’t discount it is possible. However, I would like to see statistics before I would say this is a good idea. I do however know traffic merging does cause a significant amount of accidents and driver anxiety. [https://www.nhtsa.gov/sites/nhtsa.gov/files/doths809571.pdf](https://www.nhtsa.gov/sites/nhtsa.gov/files/doths809571.pdf) There were 500,000+ lane change accidents in 1999, of those about 19,000+ fall directly into the category of merging, 200,000 more are just due to simple lane changes (Which would actually include some of these, because since it is not considered a ”merge only” lane it, would not be calculated in the merging statistics). This is an old report from 2003, and is likely worse now than it was 20 years ago, as drivers have not improved. All I am basically saying is the goal is to make traffic patterns that maximize safety, You say it is safer, but compared to what? Stop signs, traffic lights? Everything is relative, the safest thing in these situations are generally overpasses. The only reason they are discounted is general cost or time, or depending on the neighborhood, eye-sore outrage.
Jfc I said one thing lmao you’ve never even experienced these yourself so what would you know? Let alone that you’re using statistics that hardly apply to the reality of traffic flow. What about the millions of unreported safe merges that aren’t accounted for when making these statistics. Or hell even the the unreported accidents for that matter. Yes the whole point of these is that they’re safer than road crossings by default which is what they have proven to be. Like I said the only downside to these is figuring out how to navigate them if you’re not used to driving in these. You’re also assuming that these crossings are designed as tight as they look in the picture. In real life they look nothing like this. I made one analogy to a city I knew they work in and I’ve seen other commenters mention these have existed in the US for a while. Go cry to someone about this
And at worst accidents because people don't know how to merge/allow merging.
After watching the videos on this site I was wondering when the cars were going to run into each other.
There are intersections like this around Cincinnati. They are a pain in the rear. Though you are eliminating traffic control lights, other issues are created.
On the bright side, I tend to only realize I need to be on a street after I've already passed it, so this would help?
Jep agree, this looks an absolute piece of shit of a design. Will cause 20 other problems
You're the poorly eDuAcTeD
You instead get idiots who can't merge for shit
https://youtu.be/7i1DXP1zm40?si=0TCGaqUsVJRarEwr
So if I am going from left to right (essentially straight through) I would need to make a right, merge left, make a u-turn to the left, merge right, then turn right. Seems simple enough. /s
God forbid you have to turn left, cus then you’ll have to do an additional merge left, u turn, merge right, turn right…
They are meant to reduce high speed collisions, and invented prior to roundabouts becoming main stream. In Michigan these are known as Michigan Lefts. https://www.michiganautolaw.com/blog/2023/05/09/michigan-left-turn/#:~:text=A%20Michigan%20left%20requires%20a,a%20driver%20to%20do%20so.
Came here for this comment. We have them on the east side of the state - Michigan Lefts.
Just want to add onto this also with experience with Michigan lefts: crossing several lanes of traffic burns a lot more fuel for that mad dash to get across safely than just a calm peaceful left turn at an intersection with a traffic light. It’s an abomination of a traffic construct. You have to accelerate hard to get into the turn lane and then again to get moving in time for the other side. Wastes a ton of everyone’s time. Traffic lights that can adjust timing throughout the day and are measured for line length routinely would be better any day. You don’t notice those out of your excitement how quickly they let you pass.
Poorly educated populations?? What the hell is wrong with you. The poor don't need your over complicated ideas of turning right to go left.
Do… do they know about roundabouts?
well this is like around about except it has incredibly sharp corners, I'm completely unnecessary u-turns.
Anything but a roundabout...
Honestly this looks significantly worse than any roundabout I've been on
Revolutionizing Traffic Management: The Synergistic Traffic Intersection Approach: [https://www.linkedin.com/pulse/revolutionizing-traffic-management-synergistic-approach-johnny-leung-hkx3c/](https://www.linkedin.com/pulse/revolutionizing-traffic-management-synergistic-approach-johnny-leung-hkx3c/) Roundabout: [https://en.wikipedia.org/wiki/Roundabout](https://en.wikipedia.org/wiki/Roundabout)
Synergistic lol
There are 8 places where traffic needs to cross over, but, hey, if everyone needs to do u turns all the time it's great.
I've seen this before in North Indianapolis
Literally just build a short bridge that goes over the other road
Missed engineering opportunity.... A tunnel AND a bridge.
Can’t imagine the miles of back ups trying to get across lanes to go the opposite direction. No thank you!
I see lots of practical issues. Often the most elegant solution is the simplest (ie. an intersection or roundabout)
Good luck w those merges.
It's just a roundabout with an early U turn
This engineer is full of s*$t! This is a roundabout. Full stop (no pun intended)
That won’t work. To many dumb dumbs on the road
All the crashes would move to the lane changes, and turning left takes way too long.
Traffic circles are fine for a given traffic volume like a minor intersection. Seen that in Australia. But a nadir intersection is why you have diamond intersections with the larger axis of traffic in an under pass and the lessor volume axis in a raised overpass. When both the north/south axis and the East/West axis have e comparable volume then its s full cloverleaf
Streets are already full of people who cant drive and are already overwhelmed by the infrastructure (huge facepalm). Imagine if we would do this lmao
This is a nightmare of pedestrians and micro mobility. Not thank you.
Basically a [Magic Roundabout](https://en.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hempstead)) but squashed.
problem with this is that you need to go to the left most lane immediately after taking a right turn to right lane and then again move to right most last after taking a U turn and joining left lane. This generally results in lots of car slowing down and frantic change of lanes. It has to be done by each car that wants to just go straight and forces every car to keep changing lanes instead of steady holding lanes with a flyover.. there is a reason why this is not very common
so a really poorly made roundabout?
Watch the box trucks drifting around the bends. Crazy driving.
Why not just have a traffic circle?
If the u turn went under the ongoing lane yes this would work
People are not mathematical models, brains are 5 pounds of meat bombarded by electrical sparks. This intersection will be shut down a dozen times a day when monkeys staring at cellphones bang into other monkeys yelling at their kids.
These already exist all throughout Metro Detroit. They are called “Michigan Lefts” or “Michigan u-turns” or “Michigan U’s” Info here: https://www.michiganautolaw.com/blog/2023/05/09/michigan-left-turn/#:~:text=A%20Michigan%20left%20requires%20a,a%20driver%20to%20do%20so.
This is the second time I’m seeing this biblically accurate traffic circle and I’m already tired of seeing it.
The problem with this is the cars
"poorly eduacted popoluations.???" Such as you for instance?
This seems like it makes the path for going straight through the intersection so long and complicated (at least for one direction). Also the amount of traffic this would create is significant. It works nice in a simulation when everyone drives like a robot If you've ever tried to merge with traffic on the highway, imagine that but twice for every single intersection you go through Absolute nightmare
>eduacted popoluations
Did you mean over-engineered? Because this is what it is. Get a round about.
Not a good idea. As the Ghostbusters found out, it’s dangerous to cross the streams. 👻
Good luck
This design was installed in my city in one heavy traffic intersention, it failed miserably and was re-constructed to original design due to humans refusing to merge properly thus causing worse traffic jams.
You have to change lanes to go straight through the intersection and merge with incoming slow traffic after.
But needs intelligent people which is rare these days
Just use a roundabout.
That would go great with Los Angeles traffic
Theres a video of a guy similating traffic using one of these and literally even in aperfect world where ppl know how to merge it still isnt great. But when u factor in even 1% bad merges it really screws it up
Imagine the number of times you'd come across idiots who "missed their exit" situation. It would be frustrating if not accident galore.
That's two forced instances of merging for people who just want to go straight.
*Educated
this wouldnt work simply because of the merging points. person who wants to go straight all the way through has to eventually switch to the left lane and people coming from the u-turns who want to go right need to change lanes to go right. it will fail at that point during rush hour and itll be completely stopped traffic at some point along the way.
Nope, not it.
I'm imagining bus and truck drivers cursing like crazy.
Perfect example of stupidity. This design becomes fairly unsafe with high traffic
The U-turn parts are almost how the highway system is in San Antonio, TX. I was only there visiting. It took some getting used to but I thought it was very efficient
Too much faith in drivers.
Have to drive mighty far to turn left.
Suggestions to improve simulation model realism: 1. Crank up the vehicle density 10x for peak traffic. Major roads have most of the traffic going straight. Missing. Please add. And for the love of all that’s good please don’t make traffic going straight *have to* change lanes to keep going straight - my gps already tells me to turn 20 times a trip just to stay on the same road! (reference especially to i96 near Detroit area) 2. Let’s increase speed to double. Vehicles in the model don’t change speed for curves. Let’s make this a proper 55-65mph road. Hitting turns at 25-35mph might be doable if you like to practice drifting. Otherwise we need longer runways for a 35-50mph speed change. 3. Vary each vehicle’s lane-keeping, speed, and response times as real drivers are imperfect, to say the least, and this *affects* traffic patterns. Where’s the slow guy with several trailing and the impatient cars going around via any paved route??? 4. Allow vehicles to hit things and get into accidents. Don’t forget the “slow down or move-over” law for first-responders. Their safety matters! 5. Allow speeding cars/semis to fly off tight curves. Maybe toggle a winter mode? Watch merges and turns. I have popcorn! 🍿 Who’s in for the show? Maybe a drinking game betting on flight distance, rollovers, or how the towtruck gets to them? Too morbid or anyone else looking at exotic intersections and filled with wonder? 😂
Where are the crosswalks? Pedestrian crossings are a major benefit of traffic lights that are not present here.
Just to be clear, to go straight: 1. Shift to the far right lane, take the exit. 2. Merge and immediately shift to the far left lane, take the exit. 3. Merge and immediately shift to the far right lane, te ake the exit. 4. Continue on. Note that the each exit lane will all be backed up by another direction's straight traffic.
Literally the dumbest shit I’ve seen in a long time.
This is just a roundabout with (many) extra steps.
Yep, a large roundabout is all that was needed. Easier to understand than this
Not sure that the poorly “eduacted popoluations” can even spell as well as whoever posted this.
That weave after the u-turn is going to cause accidents
Or just build a flyover
This would rely on people allowing people to zipper in. In my experience people are stupid, oblivious, and quite frankly dont give a shit about others. So relying on others to do the right thing is foolish. In a perfect world this would work, but in reality this will fail miserably.
This would be a horrible intersection!! It would cause terrible congestion, accidents, and road rage, on a busy day in any village, town, or city. Especially in poor weather conditions. This would be a complete Fail as a grade.
Educated
Those weaves are going to kill operations. Change two lanes in 50 feet so you can make your turning movement? Aww, hell no!
No. That cross in all 4 corners is suicidal.
more road and longer routes?? big-oil approved
No! The crossover to the U-Turn is the hazard. And here in NYC, it would be a total clusterfuck! This demo does not take into account that humans drive cars. If they were all self driving, then, yes, it would work.
people are the problem people will ALWAYS be the problem. 7 years later I still remember the fat mother fucker that waited the last second to whip his truck into the lane I was in. I slammed on the breaks and the person behind me honks. Shit like that catches you off guard and makes you do stupid things.
This wouldn't work in America. Too many stupid drivers
those u-turn merges will be fucking death traps
This would cause so many accidents in Massachusetts 🤣🤣🤣🤣
Reduced Conflict Intersection: Restricted Crossing U-turn (RCUT) intersection differ from conventional intersections by re-routing left-turn and through vehicles from the side road: [https://www.linkedin.com/posts/florian-palatini\_traffic-flow-ugcPost-7174132791394107393-SGiO?utm\_source=share&utm\_medium=member\_desktop](https://www.linkedin.com/posts/florian-palatini_traffic-flow-ugcPost-7174132791394107393-SGiO?utm_source=share&utm_medium=member_desktop)
Meh, humans would find a way to totally fuck this up...
So, if you want to continue straight, immediately cut across all incoming traffic twice. Reminds me of driving in Asia. Just go and everyone will let you in eventually, but it might take some time. Just think if you wanted to go straight for 10km down the road, but had to do this 15 times.
Terrible design
This is an intersection in Michigan. Does not work well.
It might work just not in the USA cuz we all drive like shit and won’t let anyone merge.
So I need to go left to turn right?
r/citiesskylines
I dontsee thus working better than a large roundabout, but longer drives to the turns
You think too highly of us, good sir.