What Causes Traffic Jams?! - Mythbusters - Science Documentary

Mythbusters - S08 E14
Discover the truths behind traffic jams with the MythBusters! From brake chain reactions to freeway dynamics and circular traffic experiments, we dive into what really causes highway congestion and explore efficient traffic flow solutions. Tune in to debunk the myths and find real answers!
-------
Join the MythBusters in their thrilling quest to debunk myths, challenge urban legends, and test movie scenes in this action-packed TV series! With hosts Adam Savage and Jamie Hyneman leading the charge, buckle up for a wild ride as they employ rigorous scientific methods, high-octane experiments, and jaw-dropping explosions to uncover the truth. From epic car stunts to mind-blowing special effects, witness the power of scientific inquiry as myths are either confirmed or shattered. Get ready for an adrenaline-fueled adventure filled with excitement, humor, and the ultimate quest for knowledge. Tune in now and unlock the secrets behind the myths!
-------
Welcome to Banijay Science, your premier destination for full-length scientific documentaries and intriguing tales from the realms of engineering, technology, and beyond. Banijay Science showcases real-world applications, top-tier documentaries, and award-winning TV shows that engage and enlighten.
Immerse yourself in the captivating world of science and engineering, with content from renowned series like Mythbusters and Abandoned Engineering.
Subscribe to our channel and stay updated with every breakthrough: www.youtube.com/@BanijayScien...
#fulldocumentaries #sciencestories #factual #science #engineering #technology

[@blob0000]

Not only are roundabouts more efficient, they're also much safer because you only have to look one direction for traffic, instead of 3

[@yellowbudd9344]

You look both ways to check for pedestrians

[@silvertayuun]

@@yellowbudd9344pedestrians shouldn’t be on a roundabout…

[@kellismith4329]

If only folks would learn how to use them instead of pulling up to them and stop

[@blob0000]

@@yellowbudd9344 yes, but because they only have one direction to look for cars they can focus more on looking for pedestrians, on the other one they focus all their attention on looking for cars, and often don't even think about pedestrians.

[@yellowbudd9344]

@@Planetdune There is usually something called a crosswalk before you enter a roundabout. Pretty irresponsible to only turn your eyes towards the left before you enter. Suddenly you might hit a fellow crossing from the right. Basic traffic rules 101, no matter what country you’re from.

[@smitajky]

As a physicist I have modelled this repeatedly. I have seen it happen with pushbikes as well as cars. The key is the TIME spacing between cars and the reflex time. If the time spacing is greater than one reflex time then any action will cause a smaller and smaller reaction behind it. If the spacing is LESS than one reaction time each subsequent action is greater until a multicar pile up occurs many cars behind the trigger. If the average distance is equal to a reaction time then the wave can persist for hours. Lane changing slows down EVERYONE. As well as its cost. Every time you change lanes you cause the trigger and the situation as for braking applies. Your action causes the person behind to brake, And the person behind that to slow etc. If you are the ONLY person to do it you hold up everyone else but you get to the other end slightly faster. But if one person in every fifty changes lanes then everyone INCLUDING THE SWAPPER is much slower. There was proof of this on Geelong road. Due to roadworks the freeway was reduced to 2 lanes. The speed limit was reduced to 80km/hr BUT fixed speed cameras were mounted every single km along the road so no one could go faster. There was no overtaking and no benefit to overtaking. The average time to destination went down. i.e faster average speed. There were no traffic jams. The accident rate plummeted. Proving that if only you could get disciplined drivers to drive consistently EVERYONE got to the other end faster, safer and with less use of fuel.

[@Planetdune]

But why would I care about the traffic behind me if I lane change? I have done my own tests with keeping some cars as a reference on the highway and for sure I feel it is faster to lane change.. and in the end, I don't care what happens behind me, only what does in front. Also I feel you cannot do this test in full gridlock. Lane changing works best when the congestion does have some breathing room, as the whole point is to find this breathing room pockets by lane changing. If all lanes are all going at the same rate, it obviously won't help.

[@ondrejkratochvil4589]

@@Planetdune and i'm pretty sure there's lot of drivers with similar mindset in front of you making you going slower than necessary... traffic should be about collaboration to get everybody to their destination safely and fast (in that order), not about egos and venting frustrations...

[@markwright3161]

@@Planetdune But you're not the first person to do it. The people in front of you are causing you delays from doing the very thing you're trying to do. You'll maybe be scratching at the delay those people are causing you, but noone doing these excessive lane changes would see you and everyone else reach your destination sooner than any time you could hope for making up by changing lanes amongst everyone else trying to do the same. Another thing that works for a higher average speed is slowing earlier. You can carry more speed past a turning car, etc if you brake earlier and allow it to clear your lane from further back. It works really well with roundabouts as you can roll on without stopping from slowing earlier and continuing to move while checking for a gap to slide into. It also dramatically reduces your chances of being rear ended as a vast majority of those collisions, which is also the most common type of collision, occur when traffic is coming to a stop.

[@edc5068]

The problem is in real life outside of hypothetical models, there are drivers that would not go faster than 75 or even 70km an hour whether or not in the right of way, though sometimes this happens on the fast/overtaking lane… This is the actual factor for slow traffic (the cars in front are capping the speed of the cars that follow, in turn you are capping the speed of the cars following you) and gives incentive for drivers to lane change. If *everyone* drives at 80km/h it will remove the incentive to change lane and it will also not be possible to overtake someone without speeding

[@martinrodriguez1329]

@@Planetdune if you collaborate and care for everyone's benefit, you'll get further beyond in the end rather than going on your own benefit, there's a very interesting test about this with the What Game Theory Reveals About Life, The Universe, and Everything video and many more but this one is considerably popular that you could check to see this theory.

[@SyntheticFuture]

21 years ago Mythbusters prove that weaving sucks and round abouts are awesome. And somehow... very little has changed 😂

[@dreamboards1056]

And flat earthers have gained in ranks. We are doomed.

[@NiekNooijens]

What actually solves traffic: trains!

[@SyntheticFuture]

@@NiekNooijens ah a fellow Adam Something / Not Just Bikes enjoyer 😁

[@taikai1119]

As a german I hate seeing the second test. In Germany it's law to use the furthest right lane, if it's free, and only change into any of the other lanes, if you wish to pass something and the lane you switch into is free. Imagining that someone would pick Left Lane, and stay on it all the way, would annoy the hegg out of every german, especially since passing on the right is illegal too

[@zsoltbocsi7546]

i bet you have parallel driving there as well

[@MrMarinus18]

Yeah, it's the same in the Netherlands too. You always stay as far on the right as possible.

[@KitFuchs]

Look up the "Rechtsfahrgebot" ​@@zsoltbocsi7546

[@BabakoSen]

Ironically, it is the law in several states, including my home state, that the leftmost lane is only for passing, and there are stretches of road where semis aren't allowed in the left lane at all. Those laws just aren't really enforced except when convenient for the cops.

[@mellchiril]

on the other hand, at least we get to pat ourselves on the back for our efficient roundabouts. That made me feel better after the lane weaving chaos

[@elysiumcore]

The lack of high speed trains or modern highways, failing infrastructure is the reason - if most people decided to drive into work this would be the result - For example i live in Tokyo, most commute via trains ..then an efficient Highway is above regular street traffic - as such i rarely see congestion 😅

[@DrBarbequeSauce]

The Shinkansen single-handedly showed the world what a high-speed train can do

[@arrowghost]

Bullet trains are a game changer and sadly they only work when it's underground or on top of the road. It'll be by the Bbbbillions of Dollars for such infrastructure.

[@SMGJohn]

Tokyo has efficient public transport but it also does not have enough of it, so rush hours are not nice when everyone is going to work, surely you have experienced this.

[@cammos]

U cant compare tokyo to usa theres no comparison there too diff

[@MrMarinus18]

The US highways are fine but the lack of high speed rail is the real problem. Unfortunately the car companies have a lot of power. Elon Musk started the whole hyperloop scam mainly to sabotage California high speed rail.

[@Bandjalah]

Not only are roundabouts more efficient, they're also much safer.

[@Shizzle_My_Nizzle]

It comes from Europe, so the US wouldn't adapt it, even if it more rational...

[@brettbridger362]

I'm going to partially agree. As we use so many of them in Australia, they are very BAD when the normal flow of traffic is weighted wrong. As with all solutions, they should be checked and modelled for the situation before blindly assuming they work. Other than that, they are fine.

[@Bandjalah]

@brettbridger362 the thing is that if it comes to an intersection and you need a 4 way stop: use a roundabout. Any other case: study the best tool for the job. 4 way stops are stupidly dangerous. I'm from Portugal and what I can see (and there's stats for it) is that since we've converted everything to roundabouts the deaths have gone down a lot!

[@brettbridger362]

@@Bandjalah Gonna disagree. Maybe 99%, or more will work, but every now and then, an intersection won't work well with a roundabout, purely because of traffic flow patterns, especially during peak times. Everyone wants these black and white, 100% guaranteed solutions, but reality don't work that way.

[@rootof3vil]

@@brettbridger362 Even if there are small ociations where it is not more efficient, safety make it more efficiant in the broader sense and compensates that assumed inefficiantcy. Not only you have less focus points , you allways have to slow down allways even if there are no cars

[@rockstar6790]

By weaving between lanes, Kari managed to compress a day’s worth of stress into 1 hour 11 minutes. It’s like you are in a race for the championship with no reward at the end

[@adamradley4407]

Not too mention if everyone drove that way the chaos would be insane. Only way weaving can help is if few people do it. Doesn't benefit the group only the individual.

[@NiekNooijens]

Better to just engage autopilot and let the car drive itself through the traffic jam.

[@swilleh_]

​​@@NiekNooijensand let it crash in to the car that the ai didn't see.Gj. Autopilot wasn't made for human replacement, it was made for decreasing fatigue.

[@victorchen9170]

It's fun + you get there faster.

[@alb9022]

@@swilleh_ same with lane assist.

[@ICETuga]

How the fuck did USA still didn't adopt roundabouts? Every European driver could confirm 100% is the most efficient way to flow the traffic on an intersection

[@mycroftsanchez901]

Except when they put traffic lights on them just like they are doing in the UK now! Far better without lights.

[@MHalblaub]

@@mycroftsanchez901 There are no roundabouts with traffic lights. Either it has traffic lights or it is a roundabout. There is a reason for traffic lights at intersections no matter which form the intersection has: throughput. A roundabout has a limit for its throughput. If this limit is reached traffic jams. You can widen one lane to two, three or four lanes with traffic lights (one lane turns left, two go straight and on turns right). This is good for the rush hour but socks when you're waiting there without any other car nearby.

[@Muis33]

Simple : Insurance and Road Rage. No need for roundabouts when a crackhead is going to clear traffic in 5 minutes. Plus, he'll take 5-12 people off the road permanently!

[@kiwiciwi123]

In Holland we have turbo roundabouts , I bet they confuse even more 😅but they are even more efficient as less cars cross your way and way more cars on the roundabout

[@MrMarinus18]

Because roundabouts are especially good for traffic as a whole but take longer for the individual if the intersection is empty. The US is all about the individual at the expense of the collective. The roundabout is more efficient and it also tends to average out traffic flow on a large scale but that does mean that in a theoritical empty road it will take you longer. US roads are designed to encourage and enable high speeds and the roundabout completely conflicts with that. It is a part of the mentality that free flow is more important than speed.

[@glurp1er]

As an European, I hated the 4 way stop system when traveling in America. Plus, it heavily relies on people respecting it, and without dash am it's your words against theirs. Roundabouts are the way to go!

[@jaywalkinartist]

And then factor in that the lane weaving causes sudden breaking and therefore traffic jams for the following. In essence: no weaving less stopping.

[@trizkit995]

Excessive breaking, lane weavers, inability to merge when lanes end are all part of the recipe of shitty traffic. Weirdly the solution isn't more lanes but smarter traffic control systems like round-a-bouts.

[@attack125]

women driving is the problem.

[@mocko69]

Solution to traffic is public transport but Americans have no idea what that is apparently

[@rodh1404]

It's part of the solution. Working from home and shopping online (with delivery) helps too. And it helps a great deal if many of the places you need to go are in walking distance.

[@Wolf-ln1ml]

@@rodh1404 Shopping online _only_ helps when more or less everyone is using their car for shopping. When you use public transport or bicycles or just walk (and simply don't buy so much during one trip that you would need a car), the deliveries due to online shopping make everything _worse_ actually. Sadly, far too many US Americans seem to be opposed to the very concept of walkable cities...

[@shouldent]

No, solution is autonomous vehicles.. or somehow put humans out of the equation...

[@NiekNooijens]

@@shouldent check adam something's response to that. Tl;dw: Autonomous vehicles only increase road capacity, which just induces more demand. Also it makes it almost impossible for pedestrians to cross the road when autonomous vehicles are rushing by constantly.

[@zen1647]

​@@NiekNooijensActually there's a fair chance that autonomous vehicles could make it safer for pedestrians. Human drivers won't show down if a pedestrian could possibly step in front of them and will blast their horn if a pedestrian does that. Autonomous cars are being trained to be more cautious. I hope it works!

[@DrMillF]

If everybody would stay in their fricking lane in traffic, everyone would be faster... I hate them with all my heart

[@shinrailp1416]

We had this problem a while ago when a street i commute on was partially under construction. One lane was closed and they put this little yellow speedbump thing between the lanes to keep people from goin on the closed lane(before the actual construction) to overtake people in the normal lane Let's just say after onyl a few days you could clearly see that quite a few people clearly didn't give a damn and this poor bumper was completely crooked from idiots constantly driving over it. People will not give a shit about others as long as they can save a few seconds on their drive....

[@bobbah676]

If everyone maintained the same speed yes, but they dont.

[@DrMillF]

@@bobbah676 it's a part of the problem..

[@ffjj3380]

We don't need self driving Teslas we need central traffic control, but when I am changing lanes I make big gain because I am a pro, just doing few changes and never braking hard!

[@mrdr9534]

@@ffjj3380 Yea, but that's because You're an "above average driver"!!! Just like 90% percent of all drivers ;)

[@Tjescoo]

The biggest find on this episode was that Kari is not made to be in a car

[@Bakyt3D]

1 more advantage of roundabout is you can turn back 180 degrees

[@rootof3vil]

or 360

[@Wolf-ln1ml]

And at worst, if you don't know where to exit (due to being a stranger to the area or so), you can simply go around a second time instead of having to stop somewhere on the side of the street and hindering the traffic behind you.

[@attack125]

@@rootof3vil saw a cop do that with sirene's and lights going. went 1.75 rotations. before getting off. did this because one douche didn't stop and just drove when the light turned green. so they followed him around the roundabout to note down his licence plate. and then continue'd on to take the exit they planned from the start. guy is gonna have a pretty hefty fine in his mail.

[@hcm9999]

What Causes Traffic Jams: CARS

[@Wolf-ln1ml]

Or, _slightly_ less simple: Traffic density. Get people to use other means of transport more often (public transport, bicycles, ...), there'll be fewer cars, lower traffic density, _far_ fewer traffic jams.

[@kirosun]

Tailgaters

[@BamBamGT1]

Lousy drivers. Every day I'm in one where the sole problem is lousy drivers. Due to road works, the inner ring is partly disabled and you can't reach my high way 2. So the detour is to take the ring in the opposite direction, get on another highway which has an exit to the highway I need. As expected this causes jams leading up to the exit because of all the extra traffic. The fascinating thing is. Once you reach that exit, it should be clear skies. 500 meters of a light bend where the exit then forms a new lane on that second high way, so you don't even need to merge there. There's really no reason, once you reach that exit, to have congestions problems beyond that point. Everyone should be able to just go 70 km/h, and speed up in the final part to connect with the high way. Today, traffic was standing still on that exit. Why? No idea. It seems that some people are that lousy at driving, that simply driving forward in a light bend at a normal speed, is too hard of a challenge to pull off....

[@zen1647]

I think the opening scene with them complaining about traffic jams is mind blowing - THEY ARE the traffic jam! THEY ARE the congestion.

[@young3nsinglej]

I'm now going to share something regular from my 20+ years of driving on UK roads when dealing with roundabouts - "INDICATE YOU @#£%!" 😂

[@Wolf-ln1ml]

I'm actually starting to envy the countries where it's normal (or common or the law or whatever) to signal the opposite direction as long as you're _not_ intending to exit the roundabout (and then of course switch signal to indicate when you want to exit). Far too many only signal at the last moment (or their indicators are only visible at the last moment due to oh-so-streamlined curved fronts) that it's impossible to find out whether I'd cut off that 2nd or 3rd car with my 40t truck...

[@MrMarinus18]

16:20 That's actually why they use traffic gates to keep cars from flowing in even though there is still room. Making sure there is enough space between the cars to absorb disturbances like that creates better flow. It's very counter intitive but it is faster for people to wait at a light and then enter the free flowing freeway.

[@ryanbuckley3314]

No, it makes sense. Could you talk a bit more about it? I've always wondered about how they manage traffic in a city. To what degree are light coordinated? I get different answers when I look it up.

[@MrMarinus18]

@@ryanbuckley3314 It's about keeping car density below a certain level to make sure that the thing the mythbusters were testing doesn't happen. That the distance between cars is such that they can accomedate it.

[@MrMarinus18]

@@ryanbuckley3314 Traffic lights are different. They are computer controlled and different places do it differently. You also have different laws with different levels of priority for public transit.

[@MrMarinus18]

@@ryanbuckley3314 They also often reduce speeds prematurely as vehicle density goes up. It's faster to drive at a constant 70km/h then occasionally go 130 km/h.

[@edc5068]

As someone with decades of experience of 30km commute driving to work. I can verify that *strategic lane change* (as opposed to random lane change) gets me to the office 10 to 5 minutes earlier For example, understanding congestion patterns around bends and merging off-ramps, and also trucks going uphill. Every road has its own congestion profile, and it changes slightly when there are new apartments or off-ramps etc

[@rootof3vil]

In Europe, most of the countries, if you drive in most left lane (except UK), it will allways be fastest way to get to the point.

[@Wolf-ln1ml]

@@rootof3vil ...which is due to the law that requires you to drive on the right-most lane and *_only_* use the others for overtaking (with the exception being the middle lane(s) when you would "occasionally" overtake another vehicle). Sticking to the left-most lane is pretty much illegal under any circumstances - there will *_always_* be situations where you can be expected to move over to the right by at least one lane, and it doesn't matter whether there is another car approaching you from behind or not.

[@mikatu]

Your definition of traffic jam is wild. If you already have that much cars riding together so close, you already have a traffic jam, you don't need to hit the breaks to prove anything, since the jam is already there. A traffic jam is having the traffic slowly moving together, it doesn't need to be cars stopped. The myth was not about driving vs flying but rather train vs plane.

[@undefined40]

Ok, Kari, now come to Germany and do this at 180 km/h :) Edit: ok, a bit further into the video, it seems Grant would have been more qualified for that.

[@Ilikefire2793]

If only grant was still with us today.

[@TiborRoussou]

@@Ilikefire2793 Such a loss

[@MrMarinus18]

In Germany though you are not allowed to pass people on the right hand side, only the left. You are also expected to stay on the right if at all possible.

[@Jordan_C_Wilde]

@@MrMarinus18 You are allowed to pass people on the right during slow traffic. Otherwise if the left lane stopped, it would prevent all the other lanes from moving.

[@MrMarinus18]

@@Jordan_C_Wilde If you are legally required to be on the right by default then the only reason the left lane stops is if the others stop too. Overtaking doesn't just mean changing lanes, it means returning to the lane you came from. If the left lane stops yet the others somehow don't then you can just change lanes to the right.

[@treadingtheboards2875]

Yes, but how much are the lane weavers adding to the problem by making traffic behind them in the lane they are entering slow down. I am also seeing this on normal roads, the car beside me at the lights lays rubber at the green, weaving in and out of traffic, 7 or 8 traffic lights later, I am still beside them.

[@ddt6003]

u are not only less likely to crash in a roundabout, u can also u-turn easily, and it could handle more than 4 exit/entry

[@ChristopherAdams-tl3me]

Would rather arrive 10 minutes later but get there safely rather than risk a accident

[@GatherYeRosebudsWhileYeMay]

Thanks grand-papa I preferred the bike with the big wheel myself even the horse and carriage was much safer wa wa wa 🙄

[@Meow110]

Tori with those ladies on the plane was funny lol.

[@jaywalkinartist]

Grant stating to stop weaving whilst weaving right within the next segment. 🤣. Miss him dearly!

[@jeromepersaud7367]

This jives with what I learned in driving school waaayyyyyy back when. They told us that you'd save 2 minutes per hour by driving overly aggressive. However, it would cost you more gas, risk getting a ticket for dangerous driving and risk getting into an accident. And nowadays, you gotta worry about some overly-crazy road-rager. Not worth it.

[@thetmes6133]

I always thought weaving lane is increasing the traffic jam (you cause some cars to break more, you increase chaos and thus slow everyone down) and not so much that it's less effective than staying on the same lane

[@cammos]

Roundabouts are mad i love them esp when empty its fun to drift around

[@Defensive_Wounds]

So long as people know how to give way to you - as most do NOT know how to give way or indicate properly - I know first hand when 2 weeks ago such a driver didn't give way to me and smashed my car, probably a write off now. He was not insured! POS cnut of a driver and person!!!

[@GThu1]

In my experience, weaving works only on very familiar routes. When you learn when, where and which lanes is faster. For example, when you are not on a highway, knowing where turning lanes are and how they work might have a significant advantage. Also if you know the traffic, switching lanes are much less stressful. Because of this, I'm switching lanes with a great efficiency, if the route and the traffic is well known to me. Otherwise, indeed, it does not worth.

[@arrowghost]

I love that classic myth of plane VS car, but in summary : Plane - Faster, relaxing, but expensive with plane ticket & extra transport Car - Slower & longer, need to eat and pee, cheaper, but requires 2 drivers (1 driver is fine, but he could get tired in the long trip and needs a power nap)

[@_Briegel]

Hubs... I can only disagree. At least if you do it in Germany. I just posted the following and it fits your statement perfectly, so I'll quote myself here: In Germany, "fly or drive" is not a question. At least not if you have a real car and not an electric toy that has to go to the charging station every 60 miles if it has to drive the distance faster than 100 mph. Hamburg (fish market) - Munich (Viktualienmarkt) is around 800 km and can be done in around 7.5 hours with a good car and free highway (without driving at the limit!). By plane, bus and cab I can't make the trip in under 9 hours! My personal best time for the Kassel - Nuremberg route is under 3.5 hours. That was even faster than by ICE (train) and only cost a quarter. Why am I so sure? I studied in Bavaria and commuted between Hamburg (or Kassel, depending on whether I was staying with family or a friend) and Munich every week for over 4 years. I tested the airplane and the train. In the end, the car was always faster and, above all, much cheaper.

[@MrMarinus18]

Really? Most planes are very cramped, instructions can be quite vague, delays are frequent and you have to wait in line for a really long time.

[@TaikaJamppa]

@@_Briegel I have a fair question for you, about the highway. I am guessing you mean an autobahn, and am quite curious, do they *actually have no speed limit?* Like aaactually? I’ve heard some telling that you can actually drive there as fast as you dare, but I find that kinda… umm, impossible. I mean, if I were allowed to drive say, 200 km/h, OR OVER, I could do maybe 150 comfortably (having tested my car’s as well as my own) limits once)… I mean sure, 150 < 200 but still, scary… I must add that I am used to kinda high speeds in videogames and ”simulators” but in real car it IS different…

[@MrMarinus18]

@@TaikaJamppaOn the Autobahn you indeed have no speed limit but most cars can't go much over 140 km/h. Also if you're surrounded by cars going 130 then it's hard to go super fast yourself.

[@achdubloedesau]

@@MrMarinus18tell me you‘ve never driven on the Autobahn without telling me you‘ve never driven on the Autobahn. There are stretches that are not limited. A lot of the Autobahn is limited, quite often to 100-130kph, sometimes lower (due to construction, potholes, etc). Most cars can do 140 and more, on unlimited stretches, 200+ kph are not uncommon if traffic permits. Higher than 250 is rare as even most sportscars are limited to 250.

[@pandour]

As a European roads engineer this is funny to watch, specially the roundabout segment. Not only it's more efficient, it's also safer. It's more expensive though..

[@ctriis]

A two-lane roundabout would be even more efficient. If you're going all the way around the roundabout to the last exit (relative to the where you entered the roundabout) you use the inner lane, otherwise you use the outer lane. In Norway it is pretty standard to use your left blinker to signal that you're going the whole way around the roundabout and you switch to use your right blinker the moment you pass the exit previous to the one you're going to use. That way other cars entering the roundabout from the entry points in between my entry point and my exit who aren't themselves going all the way around can see that the outer lane will be free for them to use even when they see me passing in the inner lane. Switching the blinker to the right tells anyone driving in the outer lane behind me that I'm about to switch lanes to exit and gives them the chance to slow down a little bit if necessary. Roundabouts are also significantly safer than 4 way intersections mainly due to the fact that regardless of the rate of cars passing through per minute at any given time the traffic will move fairly slowly through the roundabout.

[@Ekitchi0]

A couple of notes about the roundabout: 1. It's much safer because even when a reckless driver blows through them like they do a 4 way stop intersection or traffic light they have to slow down quite a bit. On average there are fewer collisions on a roundabout and crucially at much lower speeds. 2. In terms of trafic flow, they should be compared to the trafic light rather than the 4 way stop sign. I believe in heavy trafic, the lights allow for a better flow than a roundabout. However in medium trafic the roundabout allow for drivers to pass through it more quickly. 3. Roundabouts can have issues if the trafic is heavily skewed in one direction. 4. If there are a lot of pedestrians, the trafic lights also get them and the cars through more quickly.

[@gts7307]

TopGear car vs plane realistic version

[@Shakes-Off-Fear]

Top Gear added the extra condition that the public transport team (Hammond and May) were not allowed to use any form of car, whereas here, Tori was able to use a Taxi.

[@TaikaJamppa]

@@Shakes-Off-FearI think Tori called it a shuttle, isn’t it like veeery short distance taxi or something?

[@rakhazidane4022]

​@@TaikaJamppai think they're mainly used for transit? like from one gate to another

[@picobyte]

I always keep extra distance in congestion. I don't care if cars cut in that space. I care about flow.

[@leopirdas6577]

Yes!!! Especially because where I live, driving is almost an extreme sport due to homicidal drivers, I always leave a shit ton of space

[@kirosun]

you are part of the solution

[@kingdom_lights]

All this internet and I just watch my fav old tv shows 😅

[@mattilindstrom]

In Finland where I live the traffic density is nothing crazy, but about 20 years ago the road engineers had an epiphany: traffic circles are the way to go. The theory was accurate, but the execution was at first lacking. There were some but they were the exception, not the rule. Two very different mistakes were made, too small a radius, and the penchant for making traffic spirals with multiple lanes (all lanes winding outward towards different exits). The latter can be impossible to navigate going in, changing lanes in the spiral, and even for people familiar with the location accurately navigating the lanes in the winter when the road markings are covered with snow.

[@OldieBugger]

All we can do now is to hope that they have learned more about roundabouts.

[@mattilindstrom]

@@OldieBugger They definitely have, but sadly the mistakes will be with us for decades to come. A major roundabout on a major road is an investment and something not demolishable/redone without severe disruption to the traffic flow.

[@MrMarinus18]

But also traffic circles aren't a magical fit-all solution. You need to use them in the right places. They are for urban places where a slow smooth flow of traffic is desireable. Trying to shoehorn traffic circles onto congested high speed roads is just a bad idea. They slow traffic down and so on a high speed road they just are a massive bottleneck. On urban streets and roads the average speed is already very low due to constant stopping/starting and many sharp turns so roundabouts make traffic more even but aren't major bottlenecks to the overall flow.

[@TaikaJamppa]

I admit, I know only very few locations nowdays that have traffic lights on them, but still, I find the Pori-Tampere highway has very well designed STOP-sign 4-way at the Pori end (crossing between Pori, Harjunpää and Ulvila, or straight to Tampere coming from Pori), and some, I think one with more traffic and multiple with less intersections with just the yield 🔻sign, as well as I think total of three or four roundabouts. Now, I live in Pori nowdays, and looking at my computer in my office, in the same direction is the closest traffic light intersection. It has fairly light traffic most of the time, but at the police station roundabout, there’s always a few cars but I have never had to stay in that intersection for too long. Then again, on the Pori-Tampere highway, only two of the crossing roads have STOP signs in the crossing I mentioned, I have had to stay behind them maybe 1-2 minutes tops, longest might’ve been when I turn left coming from Ulvila. Then again, I have come and gone in all directions on that one… quite a few times. I can’t name one intersection that has taken me longer than 2-3 minutes off the top of my head though, so… I’d say Finns know how to drive, MOST OF THE TIME.

[@mattilindstrom]

@@MrMarinus18 To be fair, any high speed ones were never constructed (unlike e.g. Farance). On the other hand, with our traffic densities, traffic lights were quite alright, taking into account the recent advances in lights sequencing algorithms.

[@Obeythebeard]

I couldn't really tell if the drivers in the roundabout test were actively using their indicators. It is of great help for those waiting to enter the if the cars already in the roundabout blink left all the way up until they will leave at the next exit. That way others know when to let someone through and when to wait, further increasing the efficiency of the roundabout. Problem is all the people who are too lazy to indicate. Some are acting as if they were thinking "It's none of your business where I'm going!".

[@ExeCratXD]

I miss mythbusters😢

[@mrdan2898]

Keep the episodes coming! 😁

[@JcGross93]

This is the most sarisfying episode. Somehow traffic is very soothing to watch.

[@oeo061]

Tip to improve airport experience: 37:40 - If you chose the moving walkway that moves in your direction, you will get to your gate faster...😄

[@neelsmostert]

If they want a more efficient roundabout, they can have two lanes in every direction. This allows the outside lanes to only make 90 degree turns, while the inside lanes can be used for 180 and 270 degree navigation, thereby increasing the number of cars in the roundabout.

[@cdpgbc-mw2kz]

The one idiot who brakes for nothing...that is how they start...

[@RB-bd5tz]

The traffic jam experiment had a self-feedback loop, while real traffic is open-ended. I don't know, but that might make a difference.

[@SyntheticFuture]

The difference it makes is that real traffic will eventually be spread out enough where the the wave dies out and doesn't feed back into itself. But the principles all still apply. One person breaking can create ghost traffic jams that last for miles.

[@squeakycleannnn]

The issue with chilling in one lane is it gets boring, the issue with getting bored is becoming sleepy, the issue with becoming sleepy is having to waste hours of time waiting for police to explain why rear ending someone was a good idea.

[@chanahasnomana]

This was a good episode. Very grounded real testing to real world scenarios.

[@Joey_Liu]

One of my all time favourites

[@albr4]

I love when they investigated real life problems, rather than just fairy tale myths. You actually learn something that could be useful in life.

[@craigh7315]

Myth busters I love all you so much I always loved watching you all on tv when I was a kid when times were a lot simpler, I used to watch you guys with my perants in my childhood and go to school the next day. Now its just good memories and hopes and dreams and tears left. now a days I really see the chemistry between all of you is so great and you don’t even get that on tv anymore, and you all make me smile god bless all you mythbusters team thanks for everything ❤️

[@Jules_Diplopia]

The thing is that roundabouts normally are used for 2 lanes of traffic, rather than a single lane. And the 400 mile car versus plane should also include a high speed train.

[@MarkyPaligs]

Protests. Imagine going to work one day for a double pay but you roll up to kids on the highway protesting that Oil thing. Unbelievable.

[@tommy2cents492]

When you design your cities for cars.... prepare to get stuck in traffic jams. I am so glad my commute is on bicycle!

[@geekytraveler5899]

In car vs plane myth you forgot one more important aspect. Planes fly by schedule. And there might be no convenient flight in next hour / day / week. While your car (if you own one) is in your garage ready to drive. + price difference and CO2 difference. - you're getting more tired from driving long distance.

[@TheBazino]

I hate everytime I discover that the traffic jam I have just been in for hours wasn't because of an actual reason, but just some aholes breaking for no reason. Which is about 80% of traffic jams.

[@Brommear]

Multi-lane roundabouts are a nightmare and I avoid them wherever I can.

[@DavidNewmanDr]

There was a test missing - car versus plane versus train over 400 miles. But to make it fair, the passenger train must have priority over freight trains and there must be public transport to both airports.

[@minthouse6338]

Passenger trains have priority over freight? You're kidding right.

[@DavidNewmanDr]

@@minthouse6338 In the civilised world they do. Europe, Japan and for high speed trains in China.

[@vanhetgoor]

Here in Europe at some places the roundabouts have been taken away and have been replaced by traffic lights. Under some circumstances traffic coming from one direction does not have a chance to enter the roundabout. When there is too much traffic from one direction. On the other hand, in some places the roundabout is expanded to a double lane roundabout, or a roundabout with very distinct lanes pointing in a certain direction. Most of the problems with traffic jams on American highways and motorways is caused by the absence of good public transport. Everybody want to be somewhere at the same time as others, a train would be super for that, mass transport is cheap and efficient, private transport is impossible if a number of cars is reached.

[@swededude1992]

I remember in my childhood I saw a digital sign telling there was an accident at exit 19. Drive carefully. The problem was there where 5 exits 19. 4 of them had no accident and the last had the accident. 4 ghostjams for nothing.

[@louisbarningham]

I always wonder what is at the front of all the traffic on the motorway and what is stopping it from flowing, especially the fast lane

[@armtdawg99]

If you keep weaving through traffic like that, you'll give yourself an anyueism.

[@MrMarinus18]

37:10 In Europe the freeway speed limit is 80 mph so the race would be ever closer. Though Tory also got lucky. Last week I flew a comparable distance but altogether the journey it took over 6 hours.

[@ChristopherAdams-tl3me]

The advantage of driving is that you can stop if you want it's cheaper and you don't have to pay for hire car or drag your luggage about

[@HappyBeezerStudios]

A fully unregulated/driver negotiated/right before left is good for low density traffic Roundabouts are great for medium density traffic. Separated, not-crossing intersections are great for high density traffic (think highway crossings) And the best way to reduce traffic is by reducing the amount of vehicles. Either by ridesharing or public transport. A bus can easily transport as many as 20-30 cars (when the cars are full, with single occupant cars it's closer to 80-120), but only needs the room of three.

[@mohl-bodell2948]

One way to think about it is to look at the flowrate of the road across a line. When all cars go at the highest speed they dare and closest distance they dare, that is the maximum carrying capacity of the road, i.e. the maximum number of cars that can pass that line per second. However, if anyone slows down for any reason, the speed goes down across that line, temporarily reducing the carrying capacity of the road at that point. Because there was a speed reduction, fewer cars can pass per second at that point for a moment. Since the carrying capacity behind is still at peak level, cars from behind bunch up at the point of reduced capacity, forcing them to slow down too, perpetuating the slow-down point. A single event can be perpetuated for hours. If anyone in the area of reduced capacity has to slow down further for some reason, that reduces the capacity of the road even further, ratcheting down the capacity until standstill. Those slow-downs are entirely unavoidable, at the very least because cars have to enter and exit the freeway, but of course many other minor random reasons too. The real issue is that the road can not handle the amount of traffic.

[@thoughtful_criticiser]

Whilst driving on the most congested highways in the UK during the late 80s and early 90s, I coined the phrase "Breakers Syndrome ". When a car get to close to the one in front and somehow panic brakes, followed by the subsequent vehicles, in heavy traffic the traffic rapidly becomes stationary but rubber necking will initiate the effect into adjacent lanes. On the busiest roads, a stationary vehicle will cause a mile of standing traffic every minute. The slightest moment of stillness will cause a quarter to half a mile, depending upon the immediate response and providing there are no collisions half a mile is usually the minimum. Throw a collision into the mix especially lane three it will be at least a mile for two vehicles. Three or four will be at least two miles. My worst experience was ten including a coach and lorry, 30 miles and 5 hours standstill.

[@stephenmoncrieff2056]

Here in Canada we use the roundabout a fair amount as well .

[@user-gz5ry6uj3w]

I used to do Montreal to NY on a regular basis. If flights were on time it was faster to fly, however flights in and out of NY are rarely on time especially in the evening.

[@jameswatadza8962]

You are supposed to change lanes when your lane stops and just as the next lane starts to move, that way you are always moving. I've tested this many times and it was not stressful... the dopamine hit of checking your rear view and seeing the cars you started out with miles behind is worth every minute.

[@drugoviic]

roundabouts become less efficient when you have multiple lanes and drivers trying to switch lanes in a roundabout or trying to exit from the inner lanes

[@theinqov]

"It's - for - our - safety" - reminds me so much of my good friend footie team mate.... super nice guy haha

[@ryancolson1212]

As we should all be aware by now, the only ways you can permanently reduce traffic is to have viable alternatives: Reliable public transport Safe bike infrastructure

[@divinemadness8117]

it's funny that a 2 hr - 50 mile drive is already considered as heavy traffic. In my place it's 3 km for 1 hour or more.

[@charleediaven6278]

Southern New Jersey has roundabouts. Many beach goers, going down the shore use them when traveling from Philadelphia and its suburbs.

[@AudunWangen]

I didn't need the test. I knew already that a roundabout is better than a 4-way stop. Most roundabouts where I live have 2 lanes inside, and that improves efficiency even more. It is also much safer. The only disadvantage is that it takes up a little more space.

[@nooboard]

38:00 The US rly need a train network. Regional, Intercity and Interstate Express. ^^ 47:00 Hamburg to Munich for example is 5:40 Minutes with train. Direct connection, ICE. It's ~ 8 to 10 hours with car for the ~800km (~500 miles).

[@daniel7242]

anyone else eyeing that black prelude?... nice

[@V.II.]

Roundabouts are efficient if the lanes are limited and traffic at medium volume. Once there are too many lanes and too many cars, like in a city, drivers have to criss cross each other and it becomes a disaster

[@kirosun]

the roundabout causes less wear on car breaks and tires, uses less fuel and it is quieter since not every car has to take off from a stand still (even when there's no traffic) however, it does need more space

[@GUIDESPERSPECTIVE]

The weaving test vs same lane test would be better for everyone involved if no one changed lanes and everyone on the road maintained the same distance, and the same speed limit. The entire flow would move way more efficiantly if everyone just stayed put, the only time you change lanes is for your exit. I bet that everyone gets to there destinations in a more safe manner and faster.

[@stevesurf22]

Roundabouts rule. Not only the reasons mentioned They use no power! Traffic lights consume a huge chunk of city budgets due to the high power bills.

[@Brommear]

Traffic flows like water and the congestion causes the equivalent of a standing wave. In water, that happens when water changes from laminar to turbulent flow. Reality is that if everybody slows down, everyone gets home sooner. Unless you weave!

[@57thorns]

Worth pointing out that the 200-400 mile range is where the train wins. Of course,if you need a car at your destination, when you are at the margin, and if you own a car, it is easier to take your car. But if you want to go city center to city cente between say Paris and Marseille, there is no competition at all. 7 hours by car, 4 by train, and 1.5 hours in the air, plus transit ttime to the airport and two hours for secutiry and boarding plus at least 30 minutes to get out of the airport... And a 7 hours car ride will be at least 10 hours with necessary breaks. And the transit time to the airport might not be so bad if you have good publice transportation...

[@roadmonitoroz]

I think weaving can give a significant difference (at least 10 - 15%) , but only under certain conditions... (1) Lots of traffic lights (2) Numerous drivers blocking others on purpose If you can get past those blockers, you can sometimes avoid a set of light (3 minutes ahead). Mix this with 10 sets of lights in less than 1 Km / 0/6 miles and you can gain a lot. However, it does certainly increase the risk of a crash. As for the freeway, the gain is a lot smaller.

[@rkalle66]

Adding pedestrians and cyclists are the real difference of roundabouts in Europe's cities. And outside of city boundaries roundabouts are minimizing fatal accidents on intersections because cars have to slow down like on bumpers. Btw they are more cost effecitve to maintain than traffic lights.

[@JoyousNightjar]

So far I have come to the roundabout vs cross road. I undertake considerable amount of driving everyday but I am located in middle east. I believe its all relative. On a busy road, in my opinion, signals are better than roundabouts. Provided timing is properly adjusted.

[@lubsnewfie6122]

Come to Prince Edward Island, roundabout capital of Canada! They took some time to get used to but now going through them is second nature. They did speed things up on what were once were very busy and congested intersections. One pet peeve I do have though, is people not using their turn signals going through the roundabouts. By law, you're still supposed to signal.

[@Lordnet]

nice experience with the plane vs car .but this has a lot of variables to consider. in the US i think it's a must to take a rental in your destination. public transportation and using carry on luggage could alter the experience. but with the current price tag of fuel (and tollbooths) . maybe fly to the destination is faster and cheaper than driving .

[@rabidsminions2079]

Endless red lights. On a nearby road Botany Rd the lights stay green forever and on that road there is hood traffic flow. On other roads the lights turn red as you approach them after accelerating from a green light.

[@AdrianWilsonBridders1234]

This so much like the M5 in the UK, but we get phantom traffic jams, all the traffic stops for no apparent reason then starts again and is repeated all the way from Birmingham to Exeter!

[@nooboard]

13:20 the minimal safety distance at 30 km/h (~20 mph) is 15 meters (~ 50 feet). It isn't possible to keep that safety distance in that circle and that's what multiplies jams. People who drive too close to each other causing even a cascade of breaking if someone only gets of the gas pedal for a second.

[@connectorservice3767]

Murphy's law: What ever lane you pick other goes faster...

[@mattaze9972]

combine the weaving into the flow of traffic and the rate for breaking is not only going to be more, but also the panic breaking of the many that change lanes not indicating or not noticing someone changing lanes until in front and slam break on harder yeah the weaver gets off quicker, but leaves behind a jam forming

[@0FlightlessBird0]

I would love to see some experiments about the timing of lights. Here in 2024, I wish all traffic signals had a camera that measured density and flow. Have all that data fed into a central system that calculated the best timing of the traffic lights.

[@DreitTheDarkDragon]

Honestly I'm now curious if bigger roundabout (one lane, not double) would be even faster than smaller one.

[@thetrampit]

I won a race by car from the office in Paris to home in Turin, versus my colleague flying. And that's 500 miles. Differences: he had to take public transport to get to the airport and home. I did overspeed, but it happened 35 yeard ago, and 100 miles was not highway.

[@sparkyfromel]

We had a recession , to pump the economy , the government launched a roundabout program , it created employment for low qualified laborers and created a demand for building materials now we have roundabout pretty much everywhere , the big thing is that it slow down the traffic without stopping it safer for everybody and less disturbing the flow than traffic lights

[@styrelsefksu4463]

Roundabouts are really good as long as they are flat and don't have trees, bushes and sculptures in the middle of them (they call it roundabout art ) witch prevents you from seeing the cars coming at from the opposite direction of you like they do here in Sweden They have put roundabouts in almost every crossing in my hometown and many of them are super small and are causing problems for trucks and busses that can barely get through them and they can get really slippery in winter time

[@generalinfo3598]

Their weaving test is flawed. Changing lanes every time just because you can, isn't typical. Also, there's multiple footages of them changing lanes to a lane with more cars for no reason.

[@philippenachtergal6077]

32:49 Another thing would be to mass test traffic and see how the percentage of people weaving impacts the overall performance

[@FlorinArjocu]

Now make the roundabout even faster and safer by adding a right lane just a bit before the roundabout. Maybe even make it a 2 lanes roundabout.

[@DreitTheDarkDragon]

I'd rather have bigger roundabout than two lanes honestly, now I wonder what difference would be. But extra turn lane is one of things which should be implemented where possible.

[@FlorinArjocu]

@@DreitTheDarkDragon Yes, they are very useful. I see them here and there in France.

[@sauliustb]

if you have the space to put bypasses in, roundabouts get even more efficient, since you don't have the "right hand turners" If you have the space to put 2-lane roundabouts in, you need drivers that know how to do it right, but you get some more efficiency. If you put the lanes at something else than a 90 degree angle, you reduce on and off times even further..