Shutup About Road Capacity

Road capacity in cities doesn't matter. But intersections do
Credit to other creators
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1:12 - 1:18
• Laminar Pipe Flow Visu...
2:12-2:32
• Intersection Capacity
7:34-7:38
/ @notjustbikes
8:07-8:12
• Drunk driver weaving b...
• Two cars almost crash ...
• Car Overtaking Crashes...
---
Thank you to Evan, Jim, Simona, Brandon, Life for helping me do the Douglas Boulevard traffic study.

[@chefnyc]

“As an American who works in Nerherlands”. That explains why the video is published at 4am EDT. Love your videos!

[@buildthelanes]

@@chefnyc 👉👈🙏

[@flyguy1237]

@@buildthelanes Did you have to become a dutch citizen or have you been able to keep your US citizenship?

[@commandbrawler9348]

netherlands* u mean

[@anotheruser9876]

@@commandbrawler9348 The Netherlands.

[@marcelmoulin3335]

Thank you for the impeccably executed video! Your analysis is spot on. "Goed gedaan!"

[@alex2143]

Thinking about roads in terms of their capacity is more of an American thing, I feel like. It kinda pidgeon holes you into thinking that more capacity = better, and by extension more road = more capacity. It kinda sends the signal that the road's only function is to move as many cars as fast as possible at all times under all circumstances. In reality, there are road users other than cars that have to either cross, or travel those roads, as well as potentially live near them. And in reality, two lanes of traffic doesn't even move that many more cars than one lane. It can even move fewer cars if it's designed wrong.

[@rvdb7363]

Maybe you could make a video on what the changes you propose would look like for the three intersections you studied before? I think it would be helpful for people to see what it looks like, what it would do to traffic flow (not much change) and how much extra space is created by bringing down the number of lanes between intersections.

[@ScramJett]

@@rvdb7363 he might not have enough time for that. But maybe Streetcraft can help out with that.

[@sheepje]

I think the point is that the intersection isn't really a problem, but the road width in between the intersections is. It's too many lanes for the "intersection capacity".

[@rvdb7363]

@sheepje yes I understand that. I just thought it would be helpful for an international audience to have a visual of what the changed situation would look like in an American context. When I comment on American urbanists with examples from my own city (Utrecht - the Netherlands) I often get the reply that our solutions would never work in the USA. A redrawn map and/or simulation of traffic flow of what actual American intersections might look like when redesigned to be one lane each direction might inspire people to think more out of the box. Reducing the number of lanes would create space for sidewalks, protected bike paths, more green etc.

[@rtq146]

I am someone non-professional, just interested in this topic, living in The Netherlands. I have the feeling the bigger picture plays always a much bigger role for the traffic design than just the street design itself. As a cyclist I don’t even care if the tarmac is red. The thing is, the entire traffic situation could perhaps be improved with replacing 3 signalized intersections, with just 1 signalised intersections and two detours to reach the other intersections, which then don’t need signals anymore. That one intersection can then be upgraded to a turbo-roundabout with non-level crossings for cyclist/pedestrians, or non-level intersections with exits/entrance towards a roundabout. The entire section between the three junctions could then have service streets next to the main road. These servicing streets convert the stroad into a road. The main road is then one lane in each direction. The service streets will be lower speed, suitable for cycling, and suitable for servicing the exits of neighbourhoods, companies, stores etc. Additionally, they could be even made one-way traffic. This high-level planning is often not covered in the urban planning video’s. But from my youth I always remember the safe cycling routes not to be ‘red tarmac cycle streets’, but ugly converted streets to low volume traffic, with a lot of exits and street parking. This low-cost conversion with a high-level plan, in my opinion this is where it all started in The Netherlands. This involves neighbourhood plans with one-way (two-way for cyclists), cutting streets and thereby convert 4-way junctions in T-junctions. Moving cycling crossings away from the main road intersections, if main roads are one-way lanes, with a middle buffer area, this makes it ideal and easy to cross for a cyclist or pedestrians often without signals at all. This high-level design is much more important then all the nifty design details of expensive street-scapes. The aim is to have a better overall traffic flow, with sufficient access to each area. Would be VERY interesting to see some before/after neighbourhood design in The Netherlands in the 80s/90s, as well as some proposals to actual field cases in the US, for instance these junctions in the video. Nice video btw! ;)

[@Ladadadada]

This one is bookmarked. I've been trying to explain to people that throughput is constrained by intersections for years and now I have an actual qualified traffic engineer saying it on the record. Along with a bunch of other counter-intuitive things such as how reducing lanes can increase throughput by allowing you to remove the signals from a signalised intersection. Perfect!

[@timgerk3262]

Love this, and you've given me words to explain a vague intuition. One rebuttal that could be included (if only time permitted) is the fact, unappreciated by one average 70-something American whom I otherwise respect very much, that lane capacity does not vary greatly with speed. The separation between vehicles at 80mph is twice the separation at 40mph, with the result that the vehicle count passing a point in an interval of time remains the same. This paradox, and overlooking the reality that driving 65 vs 55 affects total travel time negligibly, leads voters into asinine political incentives. So much waste and so much unpleasantness. There's also a fundung problem: state and federal funds are spent aggressively on high-speed roads, leaving very little for rural or urban circulation.

[@adrianthoroughgood1191]

Your comment about increasing speed not increasing capacity is indeed very counter intuitive, but if you assume people drive with safe separations then it's true. Thinking about it a bit more, it occurs to me that if you take a given mile of road and double the number of cars on it then you halve the separation which means you halve the speed. This means that although twice as many people are trying to drive along the road the half speed means there are still the same number of cars pet hour as there were before!

[@TheHoveHeretic]

Oh boy, do I ever hope SOMEONE in Brighton & Hove City Council's Highways Dept watches your output. Our old city, which lies on the South Coast of the UK at the confluence of two valleys, was built for a dirty weekend a couple of centuries ago and definitely WASN'T built with current traffic levels in mind!! Great buses, pretty good rail links, evolving cycle lanes, rubbish road junctions (no design consistency), inappropriate use of mini-roundabouts (Got Google Earth? This one is a classic 50°49'53"N 0°10'20"W). Mercifully, our bypass was completed before our economy died of boinkered stupidity.

[@roderickvannoorloos1967]

Boinkered stupidity is my favorite new phrase of the day! Here's to hoping that the good elements of your infrastructure start outweighing the bad.

[@barryrobbins7694]

Hope? Do they have public meetings?

[@ViciousDoormat]

Great video! I hope more people find your channel. I would like it if potentially you could make the video longer and dive more into the details at the end, but that's up you of course. In any case great video!

[@buildthelanes]

thanks! unfortunately i got stuck on this video for around 6 months due to life happening, but im hoping i can make shorter, more frequent and higher quality videos soon. Thanks for watching!

[@SmileyEH]

Moved from Ottawa to Haarlem this year. So cool to see all the footage of my new home :)!

[@jyutzler]

I just sat through a county meeting where they explained that the stroad in front of my apartment building is not a candidate for a road diet because it carries too much traffic. Argh.

[@therealdutchidiot]

Share this video. And there is another video on this channel of him presenting at his former university covering the same topic.

[@javierpalomares2892]

I don't understand how traffic engineers don't understand how the problem isn't capacity with roads, it's throughput. All of the stroads in the US are actually under capacity but have huge bottlenecks. That's what creates congestion. Adding more lanes, adds more capacity, which we don't need, and don't solve the bottlenecks.

[@HweolRidda]

Bad training and bad standards. And a legal system that threatens any engineer who risks doing something less stupid than the standards. My half educated opinion only.

[@roderickvannoorloos1967]

Glad to see a new video of yours, I really enjoy your content!

[@peachezprogramming]

They're called "Traffic Lights" because they cause traffic

[@purveshsane1435]

Great video! I've been trying to say this to others on urbanist communities who generally solely seem to only circle jerk the "muh induced demand" phrase ad nauseam without providing much discussion on road design itself. Good road layouts / designs / geometry doesn't only benefit pedestrians and bicyclists, but it is also for the benefit of the driver. Most urbanist communities fail to provide this crucial messaging that the opposition would have a harder time arguing against. Talking on a tangent - for things like controlled access highways in urban and suburban areas, a lot of lanes just lead to levels of complexity that humans cannot handle leading to crashes... leading to traffic jams.

[@louiszhang3050]

This is wonderful. But there's a big problem. Unless you're one of the 3.5k people that watched this video, you won't understand this. And here's why that's a problem. I actually know an intersection exactly like this that I travel through near Arlington, Virginia. The road is one lane each direction but widens to two lanes each direction for an intersection and narrows back down to one lane. Nobody uses that extra lane, because if you do, (and I do), you'll get honked at, cursed at, and blocked for being that jerk that tried to pass everyone at the traffic light. It's the same problem with zipper merges. I was driving with a friend one day and I used the extra lane, and he said, "wow, you're one of those people." I proceed to explain the exact same thing you just explained. Their response? "yeah, but still that's so rude, just wait." The problem is not that people don't understand, it's that people refuse to understand.

[@baddriversofcolga]

Haha, I got honked at today for the same thing. And this was a person that was behind me as if I was wrong for not getting behind them as the road narrowed to one lane. So bizarre...

[@x--.]

This is such a great piece of understanding the big pie, being able to latch onto strong facts is very useful.

[@brianvanderstar4048]

Thank you for expanding our knowledge! Of op z'n Nederlands; Dank je wel pik! Die gaan we onthouden

[@austinpearce8753]

Would love for an explanation on how roundabouts affect the intersections

[@buildthelanes]

I have a video about roundabouts

[@ScramJett]

Hello from Sacramento! I recognized so many of those stroads, especially Howe Ave. I have the misfortune of needing to drive on Howe once or twice a week. Sacramento seems especially bad about this, so so many stroads! I will say this...I'm a mechanical engineer, not a traffic engineer, but I've heard the "capacity" or "volume" argument so many times that it was really mind blowing finding out that it doesn't really matter, even for bike lanes (which makes sense if you think about it even for a moment). I remember looking at an "active transportation plan" for the Pocket/Greenhaven area where the sections of Florin and Meadowview leading to I5 were shown as not eligible for bike/pedestrian infrastructure because, at 40,000 cars/hour, the traffic volumes were "too high!" (Another example of "we don't ever dare take space away from cars!"). I remember thinking how absurd that was on so many levels. And this adds a new level to the absurdity. In any case, I'm looking to get out of here. I don't think California in general, or Sacramento in particular, will ever get it. There is just too many entrenched interests and too much money sloshing around in the political system to ever expect anything to change. Franklin Blvd. was supposed to get the "Complete Streets" treatment four years ago. They keep saying it's going to happen soon and then...nothing. Don't even get me started on how pathetic SacRT is these days. I'm looking at Delft as my final destination, if I don't get run over first.

[@barryrobbins7694]

The Netherlands changed because people got involved.

[@ScramJett]

@@barryrobbins7694 Nederland changed because a solid plurality, if not a majority, of the public rose up and said no. And very aggressively at that. When you have a system where 85% of all trips are by car and most people don’t really know of, or can’t visualize an alternative, then you have a vast majority who are either indifferent or hostile to change. That is the situation in America today. The Dutch stopped before really even getting started. We have literal decades of entrenchment to reverse. And it’ll probably take twice as long to reverse the damage as it took to cause it. Simply “getting involved” won’t fix that. Today’s “advocates” are too feckless and would rather beg for bread crumbs and incrementalism than demand real change. I’m pushing 50. The day when it’s no longer possible, or safe, for me to keep driving is coming, and probably sooner than I think. I don’t see America looking remotely like Nederland 20 years, or even 30 years from now. I don’t intend to be trapped in my house, experiencing cognitive decline, because I’m too old to drive and every other mode is unreliable or too dangerous. No thank you. Better to leave now while I can and move somewhere that I know is already safe and reliable for the elderly than bet on a future that is unlikely to happen in my lifetime.

[@barryrobbins7694]

@@ScramJett Sure, if you are about fifty you might not want to spend the time necessary if you won’t see significant change in your lifetime. Unfortunately, younger generations are left with all the problems that they didn’t create, with even less resources to solve them. Then there are the younger people that leave. It’s a downward spiral. The United States is a dying empire. While China has evolved, the United States has devolved.

[@barryrobbins7694]

@@ScramJett Sure, if you are about fifty you might not want to spend the time necessary if you won’t see significant change in your lifetime. Unfortunately, younger generations are left with all the problems that they didn’t create, with even less resources to solve them. Then there are the younger people that leave. It’s a downward spiral. The United States is a dying empire. While China has evolved, the United States has devolved.

[@barryrobbins7694]

@@ScramJett Sure, if you are about fifty you might not want to spend the time necessary if you won’t see significant change in your lifetime. Unfortunately, younger generations are left with all the problems that they didn’t create, with even less resources to solve them. Then there are the younger people that leave. It’s a downward spiral. China has evolved, the United States has devolved.

[@flyguy1237]

Great video. If you ever made a video on the comprehensiveness of the network like you referred to at the end I would watch it.

[@rafaowczarczyk2767]

<a href="#" class="seekto" data-time="426">7:06</a> - How to improve USA roads? 1. Remove empty and unused spaces such as parking lots. 2. Replace "stroads" with new streets having fewer lanes and more public transportation options like bus and tram lines, as well as separate lanes for bicycles. 3. Develop apartments and small local businesses such as barbershops and local cafes/restaurants (not chains like Starbucks) in the vacant spaces. 4. Establish an efficient public transportation system within the city and connecting different cities. Currently, the only options are cars or airplanes. 5. Upgrade old roads to autobahns with limited intersections.

[@HweolRidda]

0) Rewrite the design standards to reflect the difference between capacity and flow.

[@jyutzler]

None of this will do anything until America re-centralizes its land use. All the transportation problems stem from the fact that things are as far apart from each other as possible. You can't build a coherent transit or micromobility network when things are so far apart and there are few centers or corridors of activity.

[@geography_czek5699]

Nice one 👍

[@AK-ih3hx]

So do I understand this correctly: the throughput in these intersections would be max. 1800 even if there were only 3 lanes (one straight, 2 turn)? Don't the extra lanes lead to shorter waiting times at the signal?

[@buildthelanes]

Unless the intersection is gigangtic the throughput will be lower than 1800. maybe between 1000-1500. If you have multiple lanes at the intersection ITSELF, yes, this means shorter waiting times because a signal can react more dynamically to the incoming traffic. There are many more signal combinations you can do when each movement type has its own lane.

[@buildthelanes]

however extending 3-4 lanes for a mile does nothing except increase your project costs

[@AK-ih3hx]

Ah, sure. You mention this later: widen the road for the intersection/turn lanes, leave it narrow the rest of the way.

[@steemlenn8797]

(Very populist take follwing) And of course you could slim it down to 1 lane and slam a roundabout in the same space. Might not have the 1800 but 1000 or so, but it will be a lot safer and the aditional cars can just use the similar build neighboring route they would have used if that 9 lane monster would not have existed.

[@jmlinden7]

@@buildthelanes The problem with having more lanes in the intersection than in the rest of the road is that it causes more merges and lane changes, which adds conflict points. In addition, ROW's tend to be fixed-width throughout the entire length so needing extra width at the intersection means you generally also have extra width for the rest of the road that's unused (could maybe be used for street parking or smth)

[@teejaybee8222]

THANK YOU! I live in LA and I spend more time waiting at intersections than I do "in traffic". I am convinced traffic in LA (at least non-freeway driving) is bad because of the incessant insistence for almost EVERY intersection to be controlled by traffic lights "for safety".

[@mdhazeldine]

I can see some other non-capacity related use cases for dual carriageways (two lanes in each direction). 1) The ability to overtake a slow vehicle, 2) redunancy. Say a car or bus breaks down in one lane, there is a way to get around it. For arterial roads I think this makes sense. You wouldn't want the whole flow of traffic being ruined by one random event. Would I be right in thinking that in the Netherlands, if you need enough throughput that you really need 3 lanes, then this would only be done if signalised intersections were removed and you had either roundabouts or highway style intersections with on/off ramps?

[@therealdutchidiot]

In the Netherlands only highways go beyond 2 lanes per direction, and most of the highway network is 2x2. Other classes of roads never go beyond 2 lanes per direction. Now, ofcourse, roads often flare out to 3 or more directions at traffic lights, but that's never done for roundabouts. They never go beyond 2 lanes, and in most cases turbo roundabouts are used. But rounabouts aren't the perfect solution, so another solution is a smart traffic light which monitors traffic in real time. For an example of one of these: kzbin.info/www/bejne/p5eQY3yaqZ1_rsk

[@mdhazeldine]

@@therealdutchidiot thanks. I suspected so. Having visited the Netherlands a few months ago, I don't remember seeing any roads of 3 lanes each way that weren't highways. It's actually pretty rare in the UK too, although we do have some in places.

[@jyutzler]

The argument I hear is emergency vehicles - how do they get through a two-lane road at capacity? This is being used by NIMBYs as a reason not to implement road diets.

[@therealdutchidiot]

@@jyutzler Not a great argument -- at least not in the Netherlands. Either they have routes available cars don't (bus lanes, tram tracks), or they just hop on a separated bike bath. Yes, seriously, those "structures that are unfriendly to emergency vehicles" actually provide priority routes.

[@anotheruser9876]

Goes together with walkable cities, the Halloween version of car centric cities for North Americans. Zoning and such.

[@dimrrider9133]

Leuke video en doe onderhand eens iets aan die lelijke stroomkabels boven de grond. We leven niet meer in de jaren '30

[@sonicgoo1121]

Niet alle landen hebben zulke makkelijke zandgrond als wij. ;)

[@themadsamplist]

Nog een goeie 5 jaar en we zitten weer in de jaren dertig

[@reneolthof6811]

Great video, highlighting some basic truths about transportation and infrastructure!

[@PaddyReedTV]

Nice video! I always appreciate your insights. The video I loved the most was the lecture you gave at CSU Sacramento. For this format, your sound design could be improved. If you are interested in improving your audio, it can be done cheaply. Look into getting a good mic (you really don't need anything more expensive than a wired SM58), an audio interface (like a Behringer UM2), a 1 meter XLR cable, a mic stand (mine just clips to my desk), and a pair of studio headphones (I've had luck with Sennheiser). You can get a lot of this stuff used. Record with Audacity software and watch a couple tutorials on using the software tools to improve vocal quality. Also Google "microphone technique" and read a couple tips about that.

[@buildthelanes]

Please contact me on my email. Ive been trying to improve audio quality with a new mic but i seem to be stuck

[@aeiouaeiou100]

Was expecting you to also talk about difference in intersection capacity in the NL and the US. Would be an interesting comparison.

[@therealdutchidiot]

Well, considering how different traffic lights are in the US vs NL and how intersection design differs because of this you can imagine intersection capacity in NL is a lot higher, and it's not even funny by how much. I'll let Ontario Traffic Man explain (Ontario, Canada uses the same signal style as the US): kzbin.info/www/bejne/bXyzeImGbZqKprc Now, add sensors to the mix on top of the timing differences (because even with sensors the conflict resolution has to be preserved) and you see how the capacity increases by simply ensuring once a vehicle is noticed it'll almost always get a green light by the time it hits the light itself.

[@melsbov]

Good 👍

[@akisake006]

Awesome and informative video. So much can be improved if the information is based on real facts rather than the theoretical data

[@graemetunbridge1738]

My local trips in Sydney take about the same door-to-door times, comparing the bikes with the cars. (an exception is going to the main station - the bike is way faster)

[@ChrisCoxCycling]

This is brilliant, and so applicable to Australia too. Thanks for also providing some reality to the bold claims about adding bike ways too. It gets shared a lot here and I tend to cringe - nobody believes it, especially when the safest, most coherent, most connected, most direct two way bike way in Brisbane gets 4000 cyclists per day. There's benefits to them, but to overstate it with unbelievable claims just sets off people's bullshit radar.

[@Egg-mr7np]

The reason we don't have the single lane option I think,, is because car centric places think higher speed roads will get you there faster. This can't happen in a busy city, everyone has to slow down as they cross paths eventually. A single lane reduces the percieved speed though so drivers think they are at a disadvantage. Then when they are on a multi lane road it feels like it ahould be fast even though the intersections will decide how fast it actually is over a whole journey.

[@mindstalk]

I'm a car-free road-diet advocate, but I'm not convinced by the apparently argument that street width doesn't matter. Frequent traffic lights cut road capacity, sure; naively they would cut it from 1800 to 900 vehicles per lane. But you would still have benefit from having 2 through lanes instead of 1, or 3 instead of 2. I have done my own traffic counts locally, and have gotten 10 cars per minute per lane for a 4-3 converted street (one lane each way, plus turn lane; all wide), and 8-10 cars per minute per lane (usually 8, but 10 one time at 5 PM) for the baby stroad (2 lanes each way, plus turn). The more-lane street is in fact passing more cars, 960-1200 per hour. (Granted, I have not counted on any 3-lane in a direction streets, don't have one handy.) And yeah, 1200 per hour looks minimal compared to 1800 on an uninterrupted lane, but the intersections are a given. What I see is not "more lanes don't help at all" but "the extra lane would do more good as a bus lane, bike lane, light rail lane, etc."

[@KJSvitko]

Retail bicycle outlets need to do more to encourage young people and older adults to ride bicycles. Sponsoring bike trains to escort children on their rides to school would be a great start. Organizing volunteers, teachers and other to ride along would be a great start. Getting children out of minivans and onto bicycles would be healthy exercise, build independence and make society healthier. Fun ride should also be organized. Getting a local bike club or school to sponsor an annual event to a local park or trail would encourage both adults and children to ride bicycles. Getting local elected officials to help with sponsored activities would help to educate them about the need for safe, protected bike lanes and trails in their community. Offering space and coffee for local riders to meet up would also improve store traffic.

[@ScramJett]

@@KJSvitko our kids school tried “walking school buses” for a while but it lasted only a couple of months. Parents started driving their kids when the rainy season began and, despite the school’s efforts, parents stuck to the convenience of driving less than a km away rather than walking. I expect bike trains would have a similar outcome. Especially when California law stupidly requires kids to get off their bikes and walk them across the street at intersections, even though it’s faster AND safer to keep riding through the intersection. Not that traffic lights know you’re there to begin with. If you’re not a car, you don’t exist.

[@szymex22]

Speaking the truth! Capacity is so often misrepresented and pretty stupidly compared, and intersections are what matters. Also - when comparing transport modes, way too often capacity is used as a metric when the travel time would be more honest IMO.

[@AnimilesYT]

I was so scared when a channel called "build the lanes" popped up in my feed. But I'm glad you're not someone who just wants more lanes because car propaganda xD

[@HweolRidda]

Me too. The correct title is "build the lanes right" but maybe that is too long.

[@KJSvitko]

Bicycles, ebikes, electric cargo bicycles, robo taxis and escooters are great options for last mile, short distance travel. Reduced transportation costs and fossil fuels free transportation. Cities need to do more to encourage people to ride bicycles by providing SAFE, PROTECTED BIKE LANES and trails. Every adult and child should own a bicycle and ride it regularly. Bicycles are healthy exercise and fossil fuels free transportation. Electric bicycles are bringing many older adults back to cycling. Ride to work, ride to school, ride for health or ride for fun. Children should be able to ride a bicycle to school without having to dodge cars and trucks. Separated and protected bike lanes are required. It will also make the roads safer for automobile drivers. Transportation planners and elected officials need to encourage people to walk, bike and take public transportation. Healthy exercise and fossil fuels free transportation. In the future cities will be redesigned for people not cars. Crazy big parking lots will be transformed with solar canopies generating free energy from the sun.

[@HeadsetRuler]

<a href="#" class="seekto" data-time="324">5:24</a> Hey that's Eindhoven!!

[@TheBacoosta]

I'm actually almost certain that that is Amersfoort, here: maps.app.goo.gl/6Dymfphvnk35hpe69

[@tylerlegend7205]

<a href="#" class="seekto" data-time="360">6:00</a> Oh boy I know you know the extent America and Canada does

[@haipochan8938]

Is the 1800 max capacity derived from the 2 second safety distance? If so, should the max capacity not be 1500-1700 given that the average car is 4.5 m? Or is that 2 second safety distance measured from front bumper to front bumper?

[@buildthelanes]

its measured from bumper to bumper. And of course also includes car length. Realistically it will always vary a bit because its not possible to maintain a perfect 2 second following distance all the time

[@SapienzBuchse]

I always wonder why traffic engineers use a lane capacity of 1800 v/h when the minimum safe following distance is 2s. One hour is exactly 1800*2s distances, but cars also have a length and need time to pass. For a 4m car at 50km/h this is ~0.3s or 520s for all 1800 cars in an hour, giving an average following distance of 1.7s not even accounting for longer vehicles like trucks, etc. Am I alone with thinking that it is crazy to assume a capacity in official planning that relies on most drivers breaking fundamental safety rules?

[@bpcoxkr]

My main concern is if you did this in isolation youd get pure gridlock. Im in Seattle where things mostly cap at 2x2 and where freeway exits things tend to get backed up through intersections. If you applied this in places like Texas where existing freeways are super huge and I'm not sure how anything would move.

[@HweolRidda]

He did say that intersection with lights require storage space.

[@HweolRidda]

In my limited experience, the huge Texas highways are often congested because their engineers don't understand the interaction between lane design and traffic flow.

[@therealdutchidiot]

Yiou nailed it. The only way to increase throughput is by flring out roads at intersections to provide (preferably) one lane per direction and transit type so you can use a smart signal, or if traffic volumes are low enough provide a single lane roundabout. Multi lane roundabouts make no sense in an urban environment, ever. Now, for people who don't know what a smart signal is, there is this video kzbin.info/www/bejne/bXyzeImGbZqKprc and as you watch it you'll notice one thing: intersection design matters because a smart signal needs an intelligent design, and that most countries think about signal timing in a different way than depicted here. Another thing you'll only realise later on is that he's not even discussing smart signals. He's discussing very basic signals which can eventually be made smart if need be, but it's not always needed if you think about traffic differently.

[@szymex22]

Why do you think big rounadbouts are bad? I think they are great - both signalized and unsignalized ones, provided they are designed well.

[@therealdutchidiot]

@@szymex22 Multi lane roundabouts don't actually provide benefit, for the same reason adding lanes provides no benefit, and they're more dangerous. The only reason to build a multi lane roundabout is when connecting 4 lane (2x2) roads together, and if you do that, you should be using a turbo design so you don't have as many conflicts. Signalizing roundabouts is just plain silly. That's not a roundabout ,that's a junction with an artsy layout.

[@jbirzer]

Would be nice if DC DOT would watch this. The Connecticut Ave road diet (Which would only reduce it from 6 to 4 lanes) recently axed the bike lanes that were originally planned. The official reason is that they couldn't do it safely, but the businesses scream bloody murder if you try to take away street parking (Which is what the outer lanes would be used for during the day).

[@RobHOUTX46285]

Is there a capacity per hour for roundabouts vs signals? At want point is queuing 6 lanes of traffic with red lights (fixed timing, not the smart ones you have in NL) more efficient than a 2 lane roundabout?

[@tradrailfan]

What about emergency vehicles? Isn't it better to have two lanes so the ambulances can get ahead, and still leave room for other drivers to pull over?

[@therealdutchidiot]

Emergency vehicles have no issue navigating roads like these. And they can use an adjacent bikepath instead if the need arises.

[@ronvandereerden4714]

It's not about how many people a bike lane or sidewalk can carry. It is about how few a car lane can carry by comparison.

[@buildthelanes]

How much the stop and go system can carry*

[@ronvandereerden4714]

@@buildthelanes Fair.

[@BalooUriza]

I think you missed a few lanes in there. Bike lanes are lanes, too.

[@HallsofAsgard96]

It'd be interesting what a super busy real-world cycle path capacity wld be at rush hour, like outside of Amsterdam Central, i suppose

[@ScramJett]

@@HallsofAsgard96 when we were there, there was way more foot traffic around Amsterdam Centraal than bike traffic. There might be other places in Amsterdam or other cities in Nederland that have high bike traffic though. 🤔

[@HallsofAsgard96]

@ScramJett that's probably the usual case, but i meant getting an actual number count

[@HweolRidda]

Capacity is a function of time between vehicles. I suspect bike separate themselves by about 2s, which is the car design standard in the US (1800/h). So capacity (between blockages) is a function of how many parallel lines of bikes. A stream of bikes looks really dense because 2s is a short distance at bike speeds.

[@carstarsarstenstesenn]

This is actually a great video

[@flyphone1072]

<a href="#" class="seekto" data-time="101">1:41</a> don't like that... That's two seconds between each car

[@KJSvitko]

Safe, protected bicycle lanes and trails are needed so older adults and children can ride bicycles safely. More people riding bicycles and using mass transit means there are fewer cars using the roads and less congestion. Riding a bicycle is a great way to exercise. Ebikes are bringing many older adults back to cycling. Cities need to do more to encourage people to ride bicycles. Safe protected bike lanes and trails are needed so adults and children can ride safely. Speak up for bicycles in your community. Bicycles make life and cities better. Ask your local transportation planner and elected officials to support more protected bike lanes and trails. Children should be riding a bicycle to school and not be driven in a minivan. Be healthier and happier. Ride a bicycle regularly.

[@WilsonFerguson]

Is there a concern of gridlock (as 1 lane simply cannot hold as many cars as 3 lanes and thus could overflow into side streets) or does induced demand for other modes solve this problem?

[@therealdutchidiot]

Induced demand is literally caused by adding lanes for cars, specifically on highways. In urban environments adding lanes leads to useless asphalt.

[@WilsonFerguson]

@@therealdutchidiot I don't think that answers the question. I was having a conversation with my dad about this video and he brought up the idea that cutting down the number of lanes from say 3 to 1 could cause cars to overflow into side streets (and also potentially cause a gridlock if cars are backed up to the next intersection). Is this just not a problem in reality (because of, for example, inducing demand for other modes by building bike lanes or transit lanes)?

[@therealdutchidiot]

@@WilsonFerguson We don't see that problem here. At all. Now, this all depends on intersection design, traffic light patterns and such to some extent, but it's safe to say that even with the comparatively low intersection capacity in the US and Canada compared to the Netherlands road capacity cant be filled even when removing lanes and traffic itself remaining smooth just as long as roads are flared out at intersections. Intuition tells you more lanes = more capacity, but it's not true. All it effectively does is increase danger. Intersections are the main bottleneck, which American designs increases in many ways by the typical traffic light patterns, and even if they use a roundabout they use the wong design. Context matters. For example, even if a roundabout is used, it usually has multiple lanes, which doesn't work. It just introduces more conflicts without adding capacity.

[@WilsonFerguson]

@@therealdutchidiot Alright that makes sense! Thank you so much for the in-depth response, I really appreciate it.

[@barryrobbins7694]

Are there any Dutch traffic engineers that do consulting in the United States? There are so many lanes in the United States that are not necessary and can be better utilized for bike lanes, sidewalks, BRT, trams, etc.

[@HweolRidda]

Yes. I have a conflict of interest and can't name them. Google may be a help.

[@bonsai3547]

I am surching for Mandy Lane. Is Mandy Lane here?

[@tehjaxor]

Can you please link to the CROW you show at 11.00?

[@therealdutchidiot]

Unlikely, because it requires an SWOV membership. Otherwise, CROW books are available in English, and they're not even that expensive either. Google is your friend.

[@SkyeEEPY]

been trying to say this for awhile

[@usa1945.]

great video!!

[@bonsai3547]

do youhave a AI with camera to count the traffic?

[@bonsai3547]

9.05 min ...rymes good

[@charles_cody]

Lanes better be bus lanes or bike panes & not privately owned vehicles.