Drove through one of these the other day while stopping in Joplin, Missouri for a trip out west. I was halfway through the interchange before I even realized I was on a diverging diamond. It worked seamlessly.
These work way better than people think. people see the criss-cross parts and freak out. Its very very easy. just follow the lights and signs like you normally would and its virtually no different than normal.
@@Clempath The ddi by us is almost done. Looking at it from overhead it looks complicated but from ground level it's really simple. Just follow your lane lines. I think even the dumb ones won't be able to screw this one up any worse than they normally do.
@@HeelerHouse Really? There's a barrier at the two points where traffic crosses? (no) The only thing stopping a collision is the light, for which we have plenty evidence of people missing or ignoring. (DDI's are a current fad in civil engineering. The exact same effect can be had by proper programming of the lights -- traffic only flows in one direction at a time. There's very little need to spend two years rebuilding an intersection. 'tho here, the 440/Western interchange has always been one of the worst in the country -- fire up google earth to see how stupid/dangerous it's been for decades.)
@@jfbeam Does not matter how well programed a light is in a standard intersection it will always have less vehicle through put then a DD. The DD simply eliminates 2 left turns as it puts every vehical on the side for turning left whether or not you are turning left.
The first of these were built outside Paris, France, in the seventies. They reduce accidents by more than 50%. Word to the wise: It's never too late to steal a good idea.
How is it going? I have one here and I am so anxious but it's so easy. Just the slanted lights freaked me out and the lines all over freaked me out but it was seamless
I like how it keeps pedestrians in the middle, from throwing objects down to the drivers going beneath the bridge and also from being distractions atop the bridge.
@@macaroon_nuggets8008 it may be normal for a diamond but it's still a horrible design. I drive it every day and 99% of the time you end up stopping twice to get through the intersection plus have to swerve severely twice as you cross over traffic not to mention confusing because everything is backwards from a normal transition to the interstate. Major accident hazard and very poor design plus waste of money. It's typical for wasteful govt's that fleece taxpayer's money.
@@timothyclayton2573 by diamond I don't mean a *diverging* diamond. I mean normal diamond which is the intersection in place before it. Also you end up stopping twice at most interchages.
We have one in yulee, Florida at the i-95 junction. It really is very intuitive and easy to use. I also feel like it probably reduces accidents by quite a bit. It might seem confusing at first, but when you're driving it just feels like you don't have to worry about the opposite direction traffic at all.
This is a classic example of out the box thinking to solve seemingly complex problems. Incredible that this design was only thought up decades after cars were invented. I have always believe that the ultimate solution to traffic congestion is not necessarily more lanes or less cars on the road but to completely eliminate stopping at junctions. THAT is the reason for traffic congestion. If there were no red lights or stop signs, traffic would flow smoothly. One way to do that is to turn junctions into circles. But there has to be a better way. I'm sure that with 21st century technology we can come up with a multi-level design where no cars have to stop at the junction.
It's about time. But, the video neglects to mention one other important factor;. In a cloverleaf interchange, designed 65 years ago, to exit the expressway you have to slow down and cross in front of traffic that is coming onto the expressway and trying to merge and accelerate into traffic. With the amount of traffic we are experiencing today, that is very dangerous, to say the least. This new DVI pattern reduces the number of Acceleration/Deceleration lanes and eliminates the crossover. At the end of the ramp you will either turn right with the flow or turn left with a traffic control signal.
With the DDI, those going through have to two stop signals while those wanting to get on 40 do not need to stop unless there was an accident on the ramp. As for cloverleaf interchanges I hate them no matter what due to the amount of space they take up and the traffic the merging lane creates if not long enough. I have gone on cloverleafs which incorporate dual lanes which is interesting and does alleviate traffic so if someone was using the exit to turn direction from original they just stay on the inside or right-hand lane.
@@joshuacornell6667 When I was a kid growing up and learning to drive in Baton Rouge, I think there was a cloverleaf at Airline and I-12 and maybe even again at Florida Blvd. They were horrifying because you had to change so quickly. But once I got the hang of that, I actually really liked them for the most part. But there were some big holdups at a few points that you might hit.
@@jphili We got quite a few cloverleafs in and around Boston metro area, and in Worcester county area, they are a bottle neck during peak traffic times and scary most others, but a breeze when there is not much traffic at all, those would be better served by a DDI ( we have none in MA yet afaik) or a roundabout exit aka Rotary as we call them here in parts of NE where more are popping up.
I can somewhat see why these are beneficial as it cuts out the cost of bridge spans we use in SPUI's or Single Point Urban Interchanges. They're also known as Texas U turns as they're all over Texas. They work great, but are very expensive due to the cost of concrete these days.
I have yet to use either of these types of interchanges, but they seem pretty straight forward to me unlike some others who are commenting. I mainly only come across the old four ways, cloverleafs and other common types of interchanges,.
This actually looks quite clever. I'm reading lots of hand-wringing and doom & gloom predictions from the standard internet-crybabies out there, so is there some actual HARD EVIDENCE that this type of intersection has decreased travel TIMES (as well as accidents) for those few dozen places it's been used here in America? Especially in northern states where there needs to be bigger shoulders to plan for several feet of snow being plowed to the side of the road every winter? I'd love to read some more studies on this or actual numbers, not just people fearing the worst with no proof.
DJMichaelAngelo They did this on the Jimmy Carter Blvd and i85, I didnt know what they were doing until it was done and they let traffic through. It felt so weird, at first, i thought it was a temporary thing but it turned out to be a real thing. Still feels weird but I do see how it helps expedite traffic though I'm not sure if the overall confusing is really worth it. It looks interesting when you are going through it though!
This video was used to supposedly show the plan for I-40 and US-21 in Statesville, NC. Apparently it was also used for highway 123 in the original video. The problem is the video shows 123 crossing I-40 whereas US-21 goes UNDER I-40, not over as (123) shown in this video. I'm not sure if this will matter. Perhaps it will still work the same way whether it is over or under, but just harder to visualize when I know I-40 crosses over US-21.
I have yet to see an Underpass DDI where as the SPUI (Single Point Urban Interchange) has one example of being under the highway overpass. I have yet to experience using one of these but from what I see and my experience of driving Rotary.Roundabout is pretty straight forward, I do not find it complicated like some.
1. Cloverleaf without collector/distributor lane is complex (read: bad) with ramp traffic weaving. 2. Free flowing isn't always better. Traffic light controlled junctions work in many settings of service interchanges 3. Parclo >>>...>>> Cloverleaf
Cloverleaf is for freeway to freeway interchanges. DDI is for a surface street/freeway interchange. The surface streets MUST have the stop lights at each side of the diamond to work, but you would not want stop lights on a freeway to freeway interchange.
7 years later, the one by my area is working pretty well for traffic. Though I do catch a couple idiots that muck things up. Seen one guy go the wrong way. Seen one guy blow a stale light. Even seen one guy crash into one of the light poles. Not sure about the prospect of building these at every intersection, but I can see them doing wonders at high traffic intersections.
they have one of these in a area i go to once and awhile which was very well known to be slow and hard to turn on the freeway people running the red lights by 3-5cars because they been sitting at the light for 10-15mins already because of how fast the old lights would go from green to red. they put this in and omg so much better and how they have it setup they have lights for even the turn on ramps so that if a person on a bike or walking can cross without a big worry like everyone thinks not sure why i didnt see this in the video but i skimmed it, and traffic moves so much smoother at first i was like what is going on after the first time going through it was easy to figure out but we have idiot drivers everywhere that it probably will cause a issue of them driving down the wrong way but they would have to be pretty stupid to do this as they can see cars on that way facing them if they that dumb to keep going straight then take the license away because they should not be on the road. They are putting one up by where i live now and cant wait for it because it will make that so much easier to get through specially during peak rush hours.
Would it make sense to do away with the traffic lights and have an over and under pass too? This could be a non stop in the future with exit lanes to get into the mall area and future business west of the mall. Just being proactive.
Problem with that is that cars moving across the over/under pass would then have to deal with traffic exiting the freeway and turning left. The way it is set up in this video (which I assume is the way it is normally set up in real life), the cars exiting the freeway and turning left have a green light when the cars waiting to cross from right side to left side have a red light, and vice-versa.
I immediately had the same idea. While this works really well as an interchange, if the majority of the traffic just wants to go straight, this design is sub-optimal. So I thought that it would be great, if only interchangers could use the interchange and people driving straight could have a signal-free path. Now the issue is that the street would need 8 lanes total instead of 4. You would lay down an additional 4 lanes in the middle of this interchange as the overpass. Everyone keeping on the left 2 lanes (for their direction) would then just go straight over the overpass. Everyone keeping on the right 2 lanes (for their direction) would end up in the interchange as depicted in this video. Building such an interchange would be a lot more expensive, because the overpass would essentially be a bridge. The interchange would significantly grow in size. Not just more lanes, but also a lot longer.
For an enormous intersection this might work. The left turn lanes would need to be designated left turn lanes to be able to merge. Only issue is youd have three layers of traffic. To not be too abrupt the intersection would have to be quite large.
Ahhh! One of the key points mentioned here is lane markings on the pavement. I live in Illinois and upkeep is never done to the roads. That's why lane exit detection doesn't work here.
There isnt any opportunity to mess up theres barriers that block the right side of the road so you have to go to the left. And then at the end of the bridge theres a barrier that forces you back to the right. Its impossible to mess up
Although it requires a bit more space the clover leaf interchange is vastly superior. Nobody sits idling as they wait for a signal to change traffic is in constant motion.
That’s just not true at all. A cloverleaf has the same number of traffic lights as a diverging diamond or even a normal diamond. Sure, you could turn left on solid green, but that’s introducing danger. In this design, the sole purpose of the traffic lights are to alternate between two perpendicular directions of traffic that are both going straight, just like a standard 4 way intersection, but without the two (out of four total) traffic cycles for left turns. This way there are only two cycles. Plus, the biggest fault of the cloverleaf is that it also creates incredibly dangerous conflict on the freeway between cars accelerating to merge on, and cars decelerating to merge off. Diamonds, diverging diamonds, single point urban interchanges, no other common design has that. They invented partial cloverleafs specifically because that part of the cloverleaf sucked so bad. Every time I go to my sister’s house I have to go from 70 mph to 25 in like 5 seconds while trying to weave through cars going from 25 to 70. Last, the DDI basically turns every left turn on the overpass into a simple merge, just like how ramps interact with the freeway. Not only is that more free flowing and eliminate the need for those extra traffic light cycles, but it also makes it nearly impossible to merge onto the freeway going the wrong direction since you would have to make a hairpin. In a cloverleaf or diamond you could just make a normal righthand turn and boom, you turned an off ramp into an on ramp.
@@tjw4947 The cloverleafs near me don’t have the diamond on top, you’re right there’s no traffic lights on most of them which do. You still have to go around a bigass loop at 20 mph and hope no one’s gonna head for the off ramp and meet you under the overpass. There’s a reason they’re being modified into other designs and being phased out. When traffic picks up the design becomes less and less viable. The weaving is dangerous but it also causes congestion by increasing the amount of crossing over that has to be done. People in the right lane have to slow down, on the freeway, because of this design. That’s a fatal flaw. It has literally killed people. I’ll trade a couple seconds at a stoplight to not have to worry about going 25 next to people going 70. Most interchanges take the conflict and put it on the surface street. Cloverleafs go, “no, not dangerous enough. Let’s put all the conflict on the freeway where the speed is higher.” The cloverleaf is the only design that has this. I can get behind a partial cloverleaf that removes that danger, but a traditional cloverleaf? Come on. That’s like the one wrong answer you could choose
Better idea. Any four way interchange can be separated into two three-way interchanges. Let all the side street traffic merge onto the highway, and 1/4 mile down the highway thru traffic can exit. No lights, faster cheaper easier.
would not keeping the main lanes in their 'normal' place and adding a small bridge for the left turning traffic to cross over the oncoming traffic not be better as no lights are needed and the 'old' traffic on the carriageway leaves before 'new' joins?
Watch some videos on how bridges are installed or replaced, then you will see why the DDI is more feasible to that drech of an idea and the amount of work involved in comparison.
If your exit was the next one I am sure there is a n alternate route down the road, but if your exit was two or more later, then yeah that could be an issue.
You wouldn't be able to do that on most interchanges anyway, though. In that case, I guess you'd have to get on the road and then do a U-turn or somehow get on the other side of the road.
Trwent, the most common reasons someone might exit the freeway briefly before continuing in the same direction would be to stop at a gas station, or to get some fast food.
...or the name Diverging Diamond Interchange comes from the fact that it's a variation of the standard diamond interchange with the surface street diverging to the opposite site, but whatever floats your boat.
What about when a bicyclist is trying to cross the right turn area? They will have to cross the road right in front of all the cars turning right. The lane is very, very wide at that point so the bicycles will have a long, scary journey across there hoping a car doesn't come. This will be extra dangerous since the cars will be moving quickly and not expecting to have to stop
they have stop lights at the right turn area too so that if walker or bicycle decided to go across they hit the button and it turns the lights red for that part and the other traffic keeps moving its pretty smooth setup
That seems like a hotspot for blind spot accidents to me as well. Having them cross that right turn lane at a 90° angle would probably be safer. Having a red light for the right turn lane when traffic has green to go straight on would most likely even improve the traffic flow for cars as there would be less conflict with the left turning traffic in the opposite direction.
This is a valid concern, however it’s important to consider where these interchange will be placed. The DDI is focused on preventing congestion when exiting the highway, and the amount of cyclists that are in these areas are very minimal since they won’t be exiting the interstate. The benefit they provide to traffic is worth the inconvenience for cyclists, who may simply change their route, and given the area that we will see this implemented I doubt there will be many cyclists actually affected.
Except this isn't entirely what they built at Western. Parts of the old horrible, dangerous interchange are still there. And if you watch WRAL's video of people driving through it crossing lanes everywhere, this is going to be a mess for months. (there are two, compressed versions that have been around for years... Southpoint and Six Forks. Southpoint is a very busy place that's very confusing it you haven't studied where to be. Six Forks is just a weird surprise.)
If the two parts where the flow of traffic intersects and has to be regulated by traffic lights could be replaced with a bridge (*1) on each end, this would be perfect. (*1) So that instead of crossing each other, one of the roads would pass underneath the other one.
U turn: Check! Left turn: Check! Right turn: Check! Ok what if I'm driving on I-40-W, and I take the wrong exit. I want to re-enter I-40-W and take the next exit instead. How could I do that with this kind of route system? 1. U-turn to I-40-E then U-turn back to I-40-W? 2. Take Right and try to U-turn when possible? The U-turn routes are excellent because it helps, but the infinity-like routes actually make things worse because people take wrong exits a lot.
Yeah I also noticed that with these DDI as well, not to mention oversize that is over height loads needing to exit to clear the overpass low limit height. But since there is more than one way around as in other roads taking different routes to the same place, I doubt that is much an issue for those loads.
First of all, "Over Height Loads" have escorts, permits and pre determined routes. DDI does not require new overpasses, but if an overpass is too low, the police will be notified in advance (because of the permit) just as they are today, and the load is escorted over the DDI and back onto it's route.
Flyover bridges are expensive and are not a systematic approach to making a better expressway interchange in a crowded city with high property values, they take up a lot of room, and the property they take is no longer able to produce property tax, business or residential. Monster sprawling interchanges in big cities that have high property values is not good for a city, an efficient interchange system that also economizes valuable land and can even accommodate pedestrians and cyclists safely are a better deal for the cities taxpayer citizens..
Yes but a cloverleaf allows you to enter an interstate with no traffic signals I do not understand how these are better they're putting one in near my house in Greensburg and it is adding traffic signals to a place that doesn't have them
You don't even need a cloverleaf. If that bridge was a double decker with westbound traffic on top and eastbound traffic on the bottom, you could accomplish the same thing without traffic signals and without the weirdness of being to the left of oncoming headlights (confusing and dangerous). It would offer the same space savings. The only cost is that some of the ramps will need to be elevated.
Ironic how this video only has audio out the left channel when diverging diamonds are about driving on the left side of the road and eliminating left turns.
For the Netherlands, where there are cycle paths incorporated into most roads, and cycling is one of the main methods of transport, can cycle paths be accomodated into this? Please do not answer this if you are not entirely familiar with cycling in the Netherlands. Brian Fenwick.
North Carolina isn't the Netherlands. NC is a subtropical zone with temperatures below 30 most of the year up to the 43 degrees and very, very high humid--if being dredged in sweat on your morning commute was ever fun. With the major of the land being either mountainous or foothills/piedmont, steep and long inclines are faced in almost every commute. Americans live far from work in sparse and decentralized suburban communities. It's absolutely nothing like the Netherlands. Netherlands is flat, densely populated, cars are expensive, and people live urban cores. Plus it has an inferior biking system compared to the Danish and worst of all, Nederlands is full of Dutch people.
Compare this interchange to the older double diamond and certainly the cloverleaf, which are absolutely hopeless as far as directly accommodating cyclist and pedestrians safely (an American traffic engineer delusion). The modification I would make is to continue the bike path along side the road crossing the limited access road (expressway) raised up and separated from the motorist lanes, up with the pedestrian way in the center. In the NC design there is already room allocated for the bike way crossing that would certainly lifted up and separated from motorist lands in a sensible safe design I would expect from the Netherlands. Also all traffic signals are simple stop or go no turn signals, make then much safer as well.
This looks like it makes sense, but traffic going straight through the upper roadway has two traffic lights to stop at. Making only left turning traffic criss-cross at traffic lights on the upper level would speed up traffic even more and be just as safe.
With the old 4 way stop each end, those going straight through still had two lights to stop at while those making left turns also had to stop where as with this those wanting to make a left turn do not have to stop anymore, unless there was an accident on the ramp. So instead of four sets of lights at each end for 8 lights to maintain, there is now only two lights at each end for four lights to maintain. Not to mention the less total number of intersection conflict points at each intersection with this system.
Yep. The crazy people who came up with this forgot about that one. We have one of these here in north Austin, and if you exit the Ikea on the frontage road and need to go north, too bad. You're either going east or west, like it or not. Then you have to make a u-turn somewhere and figure out how to get back, in all the traffic. I've had to do it and I've watched other people do it. Oops!
Interesting, but it seems somewhat complicated. All I know is cloverleaf and some entangled roads and ramps fitted into available space without traffic signals, but possibly with some roundabouts. And for complicated crossroads like this pedestrian crossing are extremely unlikely.
An improvement over the clover leaf design. However, I question the wisdom of placing a straight thru preferential lane for bicycles to the right of a general purpose thru and right turn lane, This creates a manufactured conflict between drivers of bicycles and right turning motorists - the typical "right hook". Engineering FAIL.
Used one of these few times and I didn't see a benefit of it .... You still have to stop in most cases and for a right turn it alway been similar with a yelled sign
Far as I know and seen, most have the yield there for cyclist/pedestrians to cross when they are on their path, otherwise you do not have to yield going right, or left if those are clear.
I just thought of something... An diverging intersection It's basically an left hand intersection where it should be right-handed, with the right turns coming out and following the left turn... Idk, I just thought of it
We need the fly-over left exit and entry ramps as in the intersection of HWY 30, I-90 & 94 near Madison Wi. to be constructed at US 51 & US 12 & 18 to make a smooth flow of traffic without stops for these heavily used roads. The Diverging Diamond design would be deficient for the volume of traffic.
Is this even happening any more? They've been talking about this for almost 7 years now. Construction was supposed to start summer of 2017. We're past that......
Just got one in a local town. It is so confusing going on the left side of the highway. And in FL everyone is looking down at their cell phones while they drive. I’m avoiding this thing completely. There’s going to be tons of accidents.
This is proven with hard evidence to be more safe than what is in place. There are barriers and traffic lights and road markings. You literally can't mess it up, as I have driven through one myself. The intersection starts curving before you cross over so you have to go to the other side.
This intechange not only helps traffic, its also proven to decrease accidents by almost half. It also has a concrete barrier so you cant drive on the wrong side, to cause an accident in this, you'd have to be intoxicated.
Most probably North Carolina, with the icon of NC-123. I haven't fount that particular interchange, as the road itself is east of I-40, not too far from Greenville.
Roundabouts can get backed up badly in high traffic especially with pedestrians. People are never let in to the circle if there is a lot of traffic merging in from one direction. This just works. People don't like it simple because "it looks confusing".
I want to see this in action during a power outage or signal glitch... Seems like a lot of signal synchronization is required to keep all lanes flowing properly.
Why not a tunnel/bridge instead of traffic lights? the difference in capacity must be tremendous. Also a more general premise, don't do entangled junctions. Make individual paths to where they are going for instance a right turn doesn't need to be part of this junction, it could have happened before completely separate from the rest. Individual direct paths minimize merging and merging is the fundamental problem in traffic. Either in merging lanes or light regulated.
my left ear enjoyed this
I'm deaf in my left ear. I heard nothing.
@@breshkotashmal7362 oof
I agree
strange my right ear enjoyed it
@@udithawijekoon2549 Your headphones are backwards
Drove through one of these the other day while stopping in Joplin, Missouri for a trip out west. I was halfway through the interchange before I even realized I was on a diverging diamond. It worked seamlessly.
Range-line I-44?
These work way better than people think.
people see the criss-cross parts and freak out. Its very very easy. just follow the lights and signs like you normally would and its virtually no different than normal.
Exactly
Yeah but most people are too dumb to follow a simple line on the road. They ARE great improvements but new so people freak out.
@@Clempath The ddi by us is almost done. Looking at it from overhead it looks complicated but from ground level it's really simple. Just follow your lane lines. I think even the dumb ones won't be able to screw this one up any worse than they normally do.
Except NO special left turn lanes or need to wait for green arrows to make left turns!!
this design works phenomenally. We have multiple here in Springfield, MO and they are easy to use and eliminate collisions.
Or Reduce collisions so long as there is no distracted driver.
@@joshuacornell6667 There's literally no oppertunity to mess up. There's barriers blocking you from going on the right side.
@@HeelerHouse Really? There's a barrier at the two points where traffic crosses? (no) The only thing stopping a collision is the light, for which we have plenty evidence of people missing or ignoring.
(DDI's are a current fad in civil engineering. The exact same effect can be had by proper programming of the lights -- traffic only flows in one direction at a time. There's very little need to spend two years rebuilding an intersection. 'tho here, the 440/Western interchange has always been one of the worst in the country -- fire up google earth to see how stupid/dangerous it's been for decades.)
@@jfbeam I mean they work well enough that they reduce all crashes by 47%
@@jfbeam Does not matter how well programed a light is in a standard intersection it will always have less vehicle through put then a DD. The DD simply eliminates 2 left turns as it puts every vehical on the side for turning left whether or not you are turning left.
The first of these were built outside Paris, France, in the seventies. They reduce accidents by more than 50%. Word to the wise: It's never too late to steal a good idea.
This is an excellent idea. Heard they work great too. Helps tremendously with interstate traffic flow.
Thanks for making me think my earbuds were breaking
We’re finally getting one north of Tampa in Wesley Chapel, I-75 and Hwy 56 is always a backed up mess! Can’t wait to see the difference..
I go through there all the time. I had no idea that was what was being planned.
How is it going? I have one here and I am so anxious but it's so easy. Just the slanted lights freaked me out and the lines all over freaked me out but it was seamless
We have one where I live. It is almost complete and it really works great! No real hassles while they were constructing it either.
If it is not complete yet, how can it be in operation?
I like how it keeps pedestrians in the middle, from throwing objects down to the drivers going beneath the bridge and also from being distractions atop the bridge.
did you forget, HOW DO THE PEDESTRIANS GET TO THE MIDDLE?? They have to cross the highway!!
@@timothyclayton2573 No, that is a normal road they cross just as if it where a normal diamond interchange.
@@macaroon_nuggets8008 it may be normal for a diamond but it's still a horrible design. I drive it every day and 99% of the time you end up stopping twice to get through the intersection plus have to swerve severely twice as you cross over traffic not to mention confusing because everything is backwards from a normal transition to the interstate. Major accident hazard and very poor design plus waste of money. It's typical for wasteful govt's that fleece taxpayer's money.
@@timothyclayton2573 by diamond I don't mean a *diverging* diamond. I mean normal diamond which is the intersection in place before it. Also you end up stopping twice at most interchages.
_skirt_
I have one of these not too far from my house. At first, it seems confusing but it saves lives and at the same time eases traffic
We have one in yulee, Florida at the i-95 junction. It really is very intuitive and easy to use. I also feel like it probably reduces accidents by quite a bit. It might seem confusing at first, but when you're driving it just feels like you don't have to worry about the opposite direction traffic at all.
It’s finally done in Raleigh
Great explanation and visualization.
This is a classic example of out the box thinking to solve seemingly complex problems. Incredible that this design was only thought up decades after cars were invented. I have always believe that the ultimate solution to traffic congestion is not necessarily more lanes or less cars on the road but to completely eliminate stopping at junctions. THAT is the reason for traffic congestion. If there were no red lights or stop signs, traffic would flow smoothly. One way to do that is to turn junctions into circles. But there has to be a better way. I'm sure that with 21st century technology we can come up with a multi-level design where no cars have to stop at the junction.
ahahahaha 10x as many crossing opposite traffic connections...righttttt
Take it from a professional driver; Most idiots on the road today don't know how to handle a circle.
No.. as a truck driver, traffic circles are horrible.
It's about time. But, the video neglects to mention one other important factor;. In a cloverleaf interchange, designed 65 years ago, to exit the expressway you have to slow down and cross in front of traffic that is coming onto the expressway and trying to merge and accelerate into traffic. With the amount of traffic we are experiencing today, that is very dangerous, to say the least. This new DVI pattern reduces the number of Acceleration/Deceleration lanes and eliminates the crossover. At the end of the ramp you will either turn right with the flow or turn left with a traffic control signal.
With the DDI, those going through have to two stop signals while those wanting to get on 40 do not need to stop unless there was an accident on the ramp. As for cloverleaf interchanges I hate them no matter what due to the amount of space they take up and the traffic the merging lane creates if not long enough. I have gone on cloverleafs which incorporate dual lanes which is interesting and does alleviate traffic so if someone was using the exit to turn direction from original they just stay on the inside or right-hand lane.
@@joshuacornell6667 When I was a kid growing up and learning to drive in Baton Rouge, I think there was a cloverleaf at Airline and I-12 and maybe even again at Florida Blvd. They were horrifying because you had to change so quickly. But once I got the hang of that, I actually really liked them for the most part. But there were some big holdups at a few points that you might hit.
@@jphili We got quite a few cloverleafs in and around Boston metro area, and in Worcester county area, they are a bottle neck during peak traffic times and scary most others, but a breeze when there is not much traffic at all, those would be better served by a DDI ( we have none in MA yet afaik) or a roundabout exit aka Rotary as we call them here in parts of NE where more are popping up.
@@joshuacornell6667 "... have to two" ??
As far as I can tell, NC 123 doesn't cross I-40. It is at least 20 miles east of I-40 for its entire route.
Michigan DOT is considering one of these for University @ I-75 in Auburn Hills, Michigan.
Whoever came out with this idea is a fucking genius, never driven through one of these but I looks awesome!
Fascinating! Charlotte needs this!
Charlotte has four already! But yeah, we need more.
@@LeeKeels sorta looks like Tylova
I can somewhat see why these are beneficial as it cuts out the cost of bridge spans we use in SPUI's or Single Point Urban Interchanges. They're also known as Texas U turns as they're all over Texas. They work great, but are very expensive due to the cost of concrete these days.
I have yet to use either of these types of interchanges, but they seem pretty straight forward to me unlike some others who are commenting. I mainly only come across the old four ways, cloverleafs and other common types of interchanges,.
Beautiful!
Sounds awesome in my left ear
Wow, really cool!
This actually looks quite clever. I'm reading lots of hand-wringing and doom & gloom predictions from the standard internet-crybabies out there, so is there some actual HARD EVIDENCE that this type of intersection has decreased travel TIMES (as well as accidents) for those few dozen places it's been used here in America? Especially in northern states where there needs to be bigger shoulders to plan for several feet of snow being plowed to the side of the road every winter? I'd love to read some more studies on this or actual numbers, not just people fearing the worst with no proof.
DJMichaelAngelo They did this on the Jimmy Carter Blvd and i85, I didnt know what they were doing until it was done and they let traffic through. It felt so weird, at first, i thought it was a temporary thing but it turned out to be a real thing. Still feels weird but I do see how it helps expedite traffic though I'm not sure if the overall confusing is really worth it. It looks interesting when you are going through it though!
@Sith'ari Azithoth It's all about the money...over/underpasses are much more expensive
This video was used to supposedly show the plan for I-40 and US-21 in Statesville, NC. Apparently it was also used for highway 123 in the original video. The problem is the video shows 123 crossing I-40 whereas US-21 goes UNDER I-40, not over as (123) shown in this video. I'm not sure if this will matter. Perhaps it will still work the same way whether it is over or under, but just harder to visualize when I know I-40 crosses over US-21.
I have yet to see an Underpass DDI where as the SPUI (Single Point Urban Interchange) has one example of being under the highway overpass. I have yet to experience using one of these but from what I see and my experience of driving Rotary.Roundabout is pretty straight forward, I do not find it complicated like some.
Can you imagine the drunks on this, lol
Hawaii needs this.
I think a cloverleaf intersection is a lot less complex and requires no electricity.
I agree. But a cloverleaf takes up more space.
Also a cloverleaf can still get congested from those exiting having to slow down while those entering are speeding up. Not a good Interchange.
1. Cloverleaf without collector/distributor lane is complex (read: bad) with ramp traffic weaving.
2. Free flowing isn't always better. Traffic light controlled junctions work in many settings of service interchanges
3. Parclo >>>...>>> Cloverleaf
Cloverleaf is for freeway to freeway interchanges. DDI is for a surface street/freeway interchange. The surface streets MUST have the stop lights at each side of the diamond to work, but you would not want stop lights on a freeway to freeway interchange.
LOL and its massively more expensive and harder to build.
7 years later, the one by my area is working pretty well for traffic. Though I do catch a couple idiots that muck things up. Seen one guy go the wrong way. Seen one guy blow a stale light. Even seen one guy crash into one of the light poles. Not sure about the prospect of building these at every intersection, but I can see them doing wonders at high traffic intersections.
they have one of these in a area i go to once and awhile which was very well known to be slow and hard to turn on the freeway people running the red lights by 3-5cars because they been sitting at the light for 10-15mins already because of how fast the old lights would go from green to red. they put this in and omg so much better and how they have it setup they have lights for even the turn on ramps so that if a person on a bike or walking can cross without a big worry like everyone thinks not sure why i didnt see this in the video but i skimmed it, and traffic moves so much smoother at first i was like what is going on after the first time going through it was easy to figure out but we have idiot drivers everywhere that it probably will cause a issue of them driving down the wrong way but they would have to be pretty stupid to do this as they can see cars on that way facing them if they that dumb to keep going straight then take the license away because they should not be on the road. They are putting one up by where i live now and cant wait for it because it will make that so much easier to get through specially during peak rush hours.
We will have one of these real soon.
Would it make sense to do away with the traffic lights and have an over and under pass too? This could be a non stop in the future with exit lanes to get into the mall area and future business west of the mall. Just being proactive.
Problem with that is that cars moving across the over/under pass would then have to deal with traffic exiting the freeway and turning left. The way it is set up in this video (which I assume is the way it is normally set up in real life), the cars exiting the freeway and turning left have a green light when the cars waiting to cross from right side to left side have a red light, and vice-versa.
I immediately had the same idea. While this works really well as an interchange, if the majority of the traffic just wants to go straight, this design is sub-optimal.
So I thought that it would be great, if only interchangers could use the interchange and people driving straight could have a signal-free path.
Now the issue is that the street would need 8 lanes total instead of 4. You would lay down an additional 4 lanes in the middle of this interchange as the overpass. Everyone keeping on the left 2 lanes (for their direction) would then just go straight over the overpass. Everyone keeping on the right 2 lanes (for their direction) would end up in the interchange as depicted in this video.
Building such an interchange would be a lot more expensive, because the overpass would essentially be a bridge. The interchange would significantly grow in size. Not just more lanes, but also a lot longer.
For an enormous intersection this might work.
The left turn lanes would need to be designated left turn lanes to be able to merge. Only issue is youd have three layers of traffic. To not be too abrupt the intersection would have to be quite large.
See Also: The Cloverleaf (takes up a ton of space.)
How hard is it to follow the arrows?
NC loves the diverging diamond interchange.
I experienced on in Tennessee as well, but live in NC and first experienced one in NC.
Ahhh! One of the key points mentioned here is lane markings on the pavement. I live in Illinois and upkeep is never done to the roads. That's why lane exit detection doesn't work here.
It makes sense on paper, but it might be a little advanced for Charlotte's less-than-wonderful drivers.
There isnt any opportunity to mess up theres barriers that block the right side of the road so you have to go to the left. And then at the end of the bridge theres a barrier that forces you back to the right. Its impossible to mess up
Charlotte has had four of these for awhile now.
I still see traffic lights on the bridge. So only one lane direction can flow at a time?
I wish they did this @ keystone crossing in Indianapolis. Hope they will do it on i-69 and 465 @ Binford
Although it requires a bit more space the clover leaf interchange is vastly superior. Nobody sits idling as they wait for a signal to change traffic is in constant motion.
That’s just not true at all. A cloverleaf has the same number of traffic lights as a diverging diamond or even a normal diamond. Sure, you could turn left on solid green, but that’s introducing danger. In this design, the sole purpose of the traffic lights are to alternate between two perpendicular directions of traffic that are both going straight, just like a standard 4 way intersection, but without the two (out of four total) traffic cycles for left turns. This way there are only two cycles.
Plus, the biggest fault of the cloverleaf is that it also creates incredibly dangerous conflict on the freeway between cars accelerating to merge on, and cars decelerating to merge off. Diamonds, diverging diamonds, single point urban interchanges, no other common design has that. They invented partial cloverleafs specifically because that part of the cloverleaf sucked so bad. Every time I go to my sister’s house I have to go from 70 mph to 25 in like 5 seconds while trying to weave through cars going from 25 to 70.
Last, the DDI basically turns every left turn on the overpass into a simple merge, just like how ramps interact with the freeway. Not only is that more free flowing and eliminate the need for those extra traffic light cycles, but it also makes it nearly impossible to merge onto the freeway going the wrong direction since you would have to make a hairpin. In a cloverleaf or diamond you could just make a normal righthand turn and boom, you turned an off ramp into an on ramp.
@@alexhussey1308 Hogwash, perhaps you have near seen an actual cloverleaf interchange there are no traffic lights at all.
@@tjw4947 The cloverleafs near me don’t have the diamond on top, you’re right there’s no traffic lights on most of them which do. You still have to go around a bigass loop at 20 mph and hope no one’s gonna head for the off ramp and meet you under the overpass. There’s a reason they’re being modified into other designs and being phased out. When traffic picks up the design becomes less and less viable. The weaving is dangerous but it also causes congestion by increasing the amount of crossing over that has to be done. People in the right lane have to slow down, on the freeway, because of this design. That’s a fatal flaw. It has literally killed people. I’ll trade a couple seconds at a stoplight to not have to worry about going 25 next to people going 70. Most interchanges take the conflict and put it on the surface street. Cloverleafs go, “no, not dangerous enough. Let’s put all the conflict on the freeway where the speed is higher.” The cloverleaf is the only design that has this. I can get behind a partial cloverleaf that removes that danger, but a traditional cloverleaf? Come on. That’s like the one wrong answer you could choose
Better idea. Any four way interchange can be separated into two three-way interchanges. Let all the side street traffic merge onto the highway, and 1/4 mile down the highway thru traffic can exit. No lights, faster cheaper easier.
Question: What happens if traffic and signal lights is not working due to what ever the reason maybe like a storm passing through?
Same damn thing you would do at any intersection.
Any update fromthose that use this? I'm curious since they just built one by us.
I am not aware of ever driving on a DDI. WOW!
lucky you
They are pretty amazing.
Just got one in my town. Lets see how it goes
would not keeping the main lanes in their 'normal' place and adding a small bridge for the left turning traffic to cross over the oncoming traffic not be better as no lights are needed and the 'old' traffic on the carriageway leaves before 'new' joins?
Watch some videos on how bridges are installed or replaced, then you will see why the DDI is more feasible to that drech of an idea and the amount of work involved in comparison.
I took over a year for NCDOT to build the new one in Kannapolis
1 step away from perfection
might be getting some in MN
Only problem is If you take the exit and want to get back on the highway going the same direction
If your exit was the next one I am sure there is a n alternate route down the road, but if your exit was two or more later, then yeah that could be an issue.
You wouldn't be able to do that on most interchanges anyway, though. In that case, I guess you'd have to get on the road and then do a U-turn or somehow get on the other side of the road.
WHY would anyone want to do that? If I wanted to keep going in the same direction, I would not exit in the first place.
Trwent, the most common reasons someone might exit the freeway briefly before continuing in the same direction would be to stop at a gas station, or to get some fast food.
To do either of those things, you are going to be turning after exiting anyway.
...or the name Diverging Diamond Interchange comes from the fact that it's a variation of the standard diamond interchange with the surface street diverging to the opposite site, but whatever floats your boat.
walking path down the center will be very popular! Do cyclists have to weave from one side to the other to stay out of harms way (merges etc..)
What about when a bicyclist is trying to cross the right turn area? They will have to cross the road right in front of all the cars turning right. The lane is very, very wide at that point so the bicycles will have a long, scary journey across there hoping a car doesn't come. This will be extra dangerous since the cars will be moving quickly and not expecting to have to stop
they have stop lights at the right turn area too so that if walker or bicycle decided to go across they hit the button and it turns the lights red for that part and the other traffic keeps moving its pretty smooth setup
Easy - eliminate cyclists.
That seems like a hotspot for blind spot accidents to me as well.
Having them cross that right turn lane at a 90° angle would probably be safer. Having a red light for the right turn lane when traffic has green to go straight on would most likely even improve the traffic flow for cars as there would be less conflict with the left turning traffic in the opposite direction.
Ban cyclists. They're the scourge of the planet.
This is a valid concern, however it’s important to consider where these interchange will be placed. The DDI is focused on preventing congestion when exiting the highway, and the amount of cyclists that are in these areas are very minimal since they won’t be exiting the interstate. The benefit they provide to traffic is worth the inconvenience for cyclists, who may simply change their route, and given the area that we will see this implemented I doubt there will be many cyclists actually affected.
Okay but what is the need for differentiating the roads with a divider in the central part?
Keeps idiots from thinking they are on the wrong side of the road and crossing over.
Cool planned 10 years ago, applied this weekend on Western Blvd. It only took 10 years
Except this isn't entirely what they built at Western. Parts of the old horrible, dangerous interchange are still there. And if you watch WRAL's video of people driving through it crossing lanes everywhere, this is going to be a mess for months. (there are two, compressed versions that have been around for years... Southpoint and Six Forks. Southpoint is a very busy place that's very confusing it you haven't studied where to be. Six Forks is just a weird surprise.)
my left ear enjoyed this video
Can you make a left on red if you’re coming off the interstate ?
You can never make a left on red.
You can when turning left on a one-way.
If the two parts where the flow of traffic intersects and has to be regulated by traffic lights could be replaced with a bridge (*1) on each end, this would be perfect.
(*1) So that instead of crossing each other, one of the roads would pass underneath the other one.
Would be very expensive for a freeway-to-state road junction.
Brilliant. Rock Quarry Rd needs this extremely bad😑
Are you referring to the interchange on I-40 there? If yes then maybe can you give an explanation and say why it needs it?
2:33 what is this? The orange line? Reverse driving?
Try turning on the audio and listen. That's pedestrian traffic.
Why is there a bike lane on a highway?! Would you feel safe being only a few feet away from cars going 60mph?
U turn: Check!
Left turn: Check!
Right turn: Check!
Ok what if I'm driving on I-40-W, and I take the wrong exit. I want to re-enter I-40-W and take the next exit instead. How could I do that with this kind of route system?
1. U-turn to I-40-E then U-turn back to I-40-W?
2. Take Right and try to U-turn when possible?
The U-turn routes are excellent because it helps, but the infinity-like routes actually make things worse because people take wrong exits a lot.
Yeah I also noticed that with these DDI as well, not to mention oversize that is over height loads needing to exit to clear the overpass low limit height. But since there is more than one way around as in other roads taking different routes to the same place, I doubt that is much an issue for those loads.
First of all, "Over Height Loads" have escorts, permits and pre determined routes. DDI does not require new overpasses, but if an overpass is too low, the police will be notified in advance (because of the permit) just as they are today, and the load is escorted over the DDI and back onto it's route.
aLonelyRat #3 Pay attention to which exit is yours
#4 Proceed to next street and turn around.
Doesn’t a flyover bridge work better?
Flyover bridges are expensive and are not a systematic approach to making a better expressway interchange in a crowded city with high property values, they take up a lot of room, and the property they take is no longer able to produce property tax, business or residential. Monster sprawling interchanges in big cities that have high property values is not good for a city, an efficient interchange system that also economizes valuable land and can even accommodate pedestrians and cyclists safely are a better deal for the cities taxpayer citizens..
Well we have the first one coming to Montana and ppl can't even figure out how to use round abouts this will be entertaining to sya the least
Yes but a cloverleaf allows you to enter an interstate with no traffic signals I do not understand how these are better they're putting one in near my house in Greensburg and it is adding traffic signals to a place that doesn't have them
You don't even need a cloverleaf. If that bridge was a double decker with westbound traffic on top and eastbound traffic on the bottom, you could accomplish the same thing without traffic signals and without the weirdness of being to the left of oncoming headlights (confusing and dangerous). It would offer the same space savings. The only cost is that some of the ramps will need to be elevated.
Ironic how this video only has audio out the left channel when diverging diamonds are about driving on the left side of the road and eliminating left turns.
My dad was on the news for this
For the Netherlands, where there are cycle paths incorporated into most roads, and cycling is one of the main methods of transport, can cycle paths be accomodated into this? Please do not answer this if you are not entirely familiar with cycling in the Netherlands. Brian Fenwick.
Did you even watch the entire video? They showed the path for cyclist and the separate pedestrian path.
North Carolina isn't the Netherlands. NC is a subtropical zone with temperatures below 30 most of the year up to the 43 degrees and very, very high humid--if being dredged in sweat on your morning commute was ever fun. With the major of the land being either mountainous or foothills/piedmont, steep and long inclines are faced in almost every commute. Americans live far from work in sparse and decentralized suburban communities. It's absolutely nothing like the Netherlands. Netherlands is flat, densely populated, cars are expensive, and people live urban cores. Plus it has an inferior biking system compared to the Danish and worst of all, Nederlands is full of Dutch people.
Compare this interchange to the older double diamond and certainly the cloverleaf, which are absolutely hopeless as far as directly accommodating cyclist and pedestrians safely (an American traffic engineer delusion). The modification I would make is to continue the bike path along side the road crossing the limited access road (expressway) raised up and separated from the motorist lanes, up with the pedestrian way in the center. In the NC design there is already room allocated for the bike way crossing that would certainly lifted up and separated from motorist lands in a sensible safe design I would expect from the Netherlands. Also all traffic signals are simple stop or go no turn signals, make then much safer as well.
This looks like it makes sense, but traffic going straight through the upper roadway has two traffic lights to stop at. Making only left turning traffic criss-cross at traffic lights on the upper level would speed up traffic even more and be just as safe.
With the old 4 way stop each end, those going straight through still had two lights to stop at while those making left turns also had to stop where as with this those wanting to make a left turn do not have to stop anymore, unless there was an accident on the ramp. So instead of four sets of lights at each end for 8 lights to maintain, there is now only two lights at each end for four lights to maintain. Not to mention the less total number of intersection conflict points at each intersection with this system.
Yeah, after I gave it more thought, I agree you're right :-)
What if a person has to take an u-turn?
U-turns at intersections are forbidden, for very good reasons
Have them in Saskatchewan now
So what if a driver is northbound on the frontage road and wants to continue north to the interstate?
Yep. The crazy people who came up with this forgot about that one. We have one of these here in north Austin, and if you exit the Ikea on the frontage road and need to go north, too bad. You're either going east or west, like it or not. Then you have to make a u-turn somewhere and figure out how to get back, in all the traffic. I've had to do it and I've watched other people do it. Oops!
Sounds like someone trying to do something you should not do. Do not drive on frontage roads
Then the frontage road should be at the same grade as the interstate. Or not build these on interstates with frontage roads.
They're building one in Raleigh, NC
Interesting, but it seems somewhat complicated. All I know is cloverleaf and some entangled roads and ramps fitted into available space without traffic signals, but possibly with some roundabouts. And for complicated crossroads like this pedestrian crossing are extremely unlikely.
Not complicated at all.
wow!
sugoi!
An improvement over the clover leaf design. However, I question the wisdom of placing a straight thru preferential lane for bicycles to the right of a general purpose thru and right turn lane, This creates a manufactured conflict between drivers of bicycles and right turning motorists - the typical "right hook". Engineering FAIL.
Used one of these few times and I didn't see a benefit of it .... You still have to stop in most cases and for a right turn it alway been similar with a yelled sign
Far as I know and seen, most have the yield there for cyclist/pedestrians to cross when they are on their path, otherwise you do not have to yield going right, or left if those are clear.
Why don't we have more of these?
SupaEMT134 they just finished ours in Savannah/Port Wentworth Ga on I95 & 21. super fast.
We are getting more.
Four in Charlotte.
I just thought of something... An diverging intersection
It's basically an left hand intersection where it should be right-handed, with the right turns coming out and following the left turn...
Idk, I just thought of it
Genius!
We need the fly-over left exit and entry ramps as in the intersection of HWY 30, I-90 & 94 near Madison Wi. to be constructed at US 51 & US 12 & 18 to make a smooth flow of traffic without stops for these heavily used roads. The Diverging Diamond design would be deficient for the volume of traffic.
Actually the opposite has happened, in Springfield MO traffic backed up for 2 miles before, now less than a 1/4 mile. It is so much more efficient.
Is this even happening any more? They've been talking about this for almost 7 years now. Construction was supposed to start summer of 2017. We're past that......
Yes everywhere else in the States but not where you live.
Just got one in a local town. It is so confusing going on the left side of the highway. And in FL everyone is looking down at their cell phones while they drive. I’m avoiding this thing completely. There’s going to be tons of accidents.
Why would there be accidents if people just follow the road markings/traffic lights?
This is proven with hard evidence to be more safe than what is in place. There are barriers and traffic lights and road markings. You literally can't mess it up, as I have driven through one myself. The intersection starts curving before you cross over so you have to go to the other side.
This intechange not only helps traffic, its also proven to decrease accidents by almost half. It also has a concrete barrier so you cant drive on the wrong side, to cause an accident in this, you'd have to be intoxicated.
Only thing DDIs won't let you do: get back on the highway-direction you just got off.
It's definitely for drivers who know what they're doing.
what state is this?
Most probably North Carolina, with the icon of NC-123. I haven't fount that particular interchange, as the road itself is east of I-40, not too far from Greenville.
Missouri.
Little bit of trivia... Did you know that the Diverging Diamond Interchange is named after professional wrestler Diamond Dallas Page
The only problem I see is if you need to go straight... I'm guessing this state doesn't have service / access roads.
I can't imagine using this as a motorist. It looks hopelessly complicated.
Sounds confusing. The left sound output, not the diverging diamond.
Ingeious - but terrifying.
I don't get it. It looks like a good way to set up for a T-Bone wreck.
Only if you run the red light…
Then maybe you shouldn't be driving.
This reminds me of someone that was smoking too much glue!
Wow.
Las Vegas just finished creating one, there are already people going the wrong way. Even a semi on video going the wrong way.
uhhh... how about just a normal diamond with I don't know a slip lane.
A dumbbell interchange (two roundabouts) would be Much better.
Roundabouts can get backed up badly in high traffic especially with pedestrians. People are never let in to the circle if there is a lot of traffic merging in from one direction. This just works. People don't like it simple because "it looks confusing".
I want to see this in action during a power outage or signal glitch... Seems like a lot of signal synchronization is required to keep all lanes flowing properly.
A major traffic accident at either crossover point effectively shuts down all north-south traffic. This is a nightmare.
Well, duaaaah. Any major accident shuts down traffic anyhow.
How does this work in a power failure situation and the redlights are non-fuctional?
Woah I have an even better solution! Trains!
Why not a tunnel/bridge instead of traffic lights? the difference in capacity must be tremendous.
Also a more general premise, don't do entangled junctions. Make individual paths to where they are going for instance a right turn doesn't need to be part of this junction, it could have happened before completely separate from the rest. Individual direct paths minimize merging and merging is the fundamental problem in traffic. Either in merging lanes or light regulated.
That would be great if funding were unlimited. Far too costly to do that.
@@ZeusAVI no that's a mindless reaction. Think single direct lanes instead of 6 lane indirect.
@@sharpfinch5354 no, it would not. maybe think about things instead of thoughtless kneejerk conclusions like that.
DCMi interchange was supposed to do that job, but no such interchange has been constructed.