• 9tr6gyp3@lemmy.worldEnglish
      0·
      1 year ago

      Yeah ideally you put 3 seconds between you and the car in front of you. Gives a nice, springy cushion to not brake as much. Your mechanic will also be surprised how much longer your brakes last.

      • merc@sh.itjust.works
        0·
        1 year ago

        If you’re in traffic (i.e. if you are part of the traffic) and you leave a 3 second gap between you and the car in front of you, another car will drive into that gap. If you back off to create another 3 second gap, it will happen again. Even worse, if you hit the brakes to create that three second gap, even if it’s very lightly, you might cause an even worse traffic jam behind you.

        • Rhaedas@fedia.io
          0·
          1 year ago

          If you’re still moving with traffic, why do you care that someone got in front of you? If you’re slowing so much that lots of people are getting in front at one time, then you’re the obstacle. A 3 second gap changes with speed, if it’s slow traffic that’s less than a car length. And if some asshole muscles their way into a gap unsafely, let them. You’ll still get to your destination far faster than if you hit each other or cause some road rage stupidity because of who is in front.

          Driving brings out the worst in people for no gain at all.

          • merc@sh.itjust.works
            0·
            1 year ago

            If you’re still moving with traffic, why do you care that someone got in front of you?

            Because you no longer have a 3 second gap so you can no longer safely react to something happening in front of you.

            If you’re slowing so much that lots of people are getting in front at one time, then you’re the obstacle.

            That’s my point. If you keep trying to make a 3 second gap and it keeps being filled in, you’re going to cause a traffic problem.

            A 3 second gap changes with speed, if it’s slow traffic that’s less than a car length

            Technically, sure. If you’re driving at less than 5 km/h and people on foot are passing you, then yes, you can have a 3 second gap with less than 1 car length. But, if you’re driving at less than 5 km/h are you really driving, or are you effectively stopped in traffic?

            • 9tr6gyp3@lemmy.worldEnglish
              0·
              1 year ago

              If all these people are merging in front of you, then the adjacent lanes are moving a lot better, which is helpful for traffic. Less braking is the goal, and if 2 or more lanes aren’t braking as much because you left some space in front of you, then traffic should flow much better.

        • iAmTheTot@sh.itjust.works
          0·
          1 year ago

          “if you leave a 3 second gap, there will be enough space for others to safely merge into that space as they need to”

          • merc@sh.itjust.works
            0·
            1 year ago

            And after they do, there will no longer be a 3 second gap, and you’re now driving too close to the person in front of you.

            • 9tr6gyp3@lemmy.worldEnglish
              0·
              1 year ago

              You don’t have to brake and maintain a hard 3 seconds between gap. Just let off the gas a bit let it slowly restore itself. That gap is there so cars can move in and out as freely as they need.

              • merc@sh.itjust.works
                0·
                1 year ago

                Depends on how aggressively someone merges in front of you, and what they do once they’re in your lane. Some people will merge way too closely. Some people will merge then slow down suddenly. Sometimes you do need to brake.

                • 9tr6gyp3@lemmy.worldEnglish
                  0·
                  1 year ago

                  If they merge in your lane and then brake, then thats on them, not you. Yes, you will have to brake, but its not you that is being the bad driver. Just create more space between you and the car in front of you again.

                  You could also look into merging into a different lane temporarily until space is restored.

      • Rhaedas@fedia.io
        0·
        1 year ago

        I’ve always said that if you’re using your brakes on the highway and it’s not for an emergency stop, you’re too close to the car in front of you. Even if they’re the type that are on and off the brake constantly, if their speed isn’t changing much you shouldn’t need to follow their example. Of course I try to get out from behind them because they are like crying wolf and one of those brakes might be for real.

        When caught in a traffic jam I look for a semi to get behind. They won’t accelerate fast like some car drivers do, and they don’t stop as fast either. Plus they can see better if things area really starting to move or not. Keep a few car lengths behind them and while everyone is doing the start and stop motions, I’m keeping a slow but steady speed usually without needing to brake at all. It’s also less stressful.

        • Omgpwnies@lemmy.worldEnglish
          0·
          1 year ago

          I don’t always hang out behind a semi when just doing daily driving, but I will 100% camp out behind one when pulling my trailer - massive fuel savings from reduced wind resistance.

      • iAmTheTot@sh.itjust.works
        0·
        1 year ago

        Too many people were taught, and still teach, the “two car’s length” rule. Which is awful. 2 to 3 seconds is much better and intuitive to figure out.

        You say 3, which is great, but I’d settle for 2. Most people on the highways around me leave more like 0.5; I sincerely think the vast majority of people greatly overestimate the amount of space in front of them to the next car.

        • merc@sh.itjust.works
          0·
          1 year ago

          Two car lengths is ridiculously close. The average car is approx. 4.5m in length. Two car lengths is 9m. The average human reaction speed to visual stimuli is approx 250 milliseconds. At 100 km/h (28 m/s) you would travel 7 metres in that time, and that’s just the time for you to notice the stimulus and react, not to choose an appropriate action. If you’re 2 car lengths behind and the car in front of you brakes hard, you’re going to hit it.

          2 seconds behind is 56 metres behind, or 12.5 car lengths. 3 seconds is 18.5 car lengths. Even 0.5 seconds is 3 car lengths. Not enough to safely react to the car in front of you doing something unexpected, but not the tailgating that 2 seconds implies.

  • ThePantser@sh.itjust.worksEnglish
    0·
    1 year ago

    It’s the people not zipper merging correctly. You have idiots entering that are not up to speed and you have idiots breaking for the idiots not up to speed.

    On ramps should be required to have their lane not end abruptly which causes the panic. The on ram should continue for at least a 1/4 mile.

    • chuckleslord@lemmy.world
      0·
      1 year ago

      Cars cause traffic. Cars changing lanes causes traffic. Cars merging causes traffic. Only solution, get rid of the cars and the system built to cater to them.

      • eatCasserole@lemmy.world
        0·
        1 year ago

        This is the correct answer. There isn’t a city on earth that has fixed congestion by building for more cars. It’s the places that build for trains and bikes that are best for driving, ironically.

    • Rhaedas@fedia.io
      0·
      1 year ago

      The best flowing highways I’ve ever seen were ones where the on ramp didn’t end, but became the off ramp for the next exit. Obviously you can’t have that everywhere, but it’s basically a free flow lane that gives time for adjustment. I’ve also seen on ramps (older ones) that aren’t much more than a turn lane, and dangerous if you don’t know the area and traffic patterns.

      • FireRetardant@lemmy.world
        0·
        1 year ago

        My area kinda has this except the on ramp ends quickly merging into the right lane, then the off ramp starts almost immediately after. It makes traffic worse as cars trying to get on cannot merge effectively because cars want to be in that lane to exit. I find the best flow is having the off ramp before the on ramp, which minimizes right lane conflicts.

      • bananaslug4@lemmy.blahaj.zone
        0·
        1 year ago

        The issue with this style of lane design is it basically doubles the amount of lane changes that lane experiences, which can make it the most dangerous possible space if exits are close together. I’ve lived around Dallas. It’s scary.

    • Gork@sopuli.xyz
      0·
      1 year ago

      Adding to this, more collector-distributor roads that parallel the highway on both sides to reduce the weaving of people entering and exiting.

      This is also why I hate cloverleaf highway intersections, the merge period is way too short and the speed delta can be high.

    • UnderpantsWeevil@lemmy.worldEnglish
      0·
      1 year ago

      people not zipper merging correctly

      Zipper merging is more complicated than driving straight forward and requires both lanes to slow down significantly relative to the cars in front and behind them.

      • FireRetardant@lemmy.world
        0·
        1 year ago

        The biggest issue with zipper merging is humans need to not be selfish for it to work. Its very efficient when moving well and everyone is in turn, as soon as 1 asshole sneaks in or prevents a merge, it causes the entire flow to stop.

        • UnderpantsWeevil@lemmy.worldEnglish
          0·
          1 year ago

          The biggest issue with zipper merging is humans need to not be selfish for it to work.

          The biggest issue is that humans need to be aware of all the cars around them. That means using side and rear mirrors, leaving appropriate space for larger vehicles, keeping track of your place in the line, and - also, yes, not being selfish.

          Its very efficient when moving well

          If you’ve ever been alongside a semi during a zipper merge, you’d know that’s not true. Their visibility is limited and the vehicle is huge, so they have to move at a glacial pace to complete the merge. Then the people in the leading/trailing positions need to open up a much larger gap than with a traditional car, complicated by the fact that they may not know exactly how big the truck they’re letting in is. And heaven help if there’s something hanging off the back of the vehicle. That’s scary, so it causes nervous drivers to try and get away from the rear of the larger vehicle, which further snarls the traffic.

          Like, as a procedure executed by a machine with perfect information of all elements involved, its efficient. As a game theory exercise between individual drivers of different skill and temperament, riding in vehicles of varying sizes, on a road with obstructions and other potential hazards, it is decidedly not efficient.

    • eatCasserole@lemmy.world
      0·
      1 year ago

      I’ve literally seen a test with 4 cars driving around a circle, and they tell the drivers, “go at a consistent speed and maintain the distance in front of you” and after 5 minutes they’re all bunched up on one side of the circle. No amount of zipper merging and nice ramps will fix this.

  • YoSoySnekBoi@kbin.earth
    0·
    1 year ago

    Most traffic jams actually act as a kind of compression wave moving backwards through traffic. Something as small as a squirrel running across the road can cascade into an hour-long jam.

    One person brakes, then the person behind them, then the person behind them, but each time they are getting closer to each other (nobody stays equidistant from the car in front of them when braking). This causes a greater and greater slowdown as more cars are compacted into a tighter space, which travels backwards in traffic like a wave. Often the person who caused it doesn’t even realize anything happened.

    A lot of mapping software actually estimates a given traffic slowdown by treating traffic as a fluid with a wave moving backwards through it.

    • kryptonianCodeMonkey@lemmy.world
      0·
      1 year ago

      That’s also why the best way to relieve traffic is to go at a slow even pace without braking. Every time the someone in heavy traffic runs up the ass of another car and brakes hard, or swerves into the “faster” lane and make someone else brake to not hit them, they cause another brake wave. If you have a few cars intentionally just hanging back and cruising with a big enough gap between them and the cars jocking for position in traffic in front of them, then their brake waves do not propogate behind you and eventually traffic just picks up pace again.

      • OR3X@lemmy.world
        0·
        1 year ago

        Yeah, in theory it’s great but every time I try it people just cut in front of me then slam on brakes causing me to have to brake then adjust then repeat ad nauseam. People suck.

        • fleck@lemmy.world
          0·
          1 year ago

          This is why I thought that maybe it would be good to have some kind of pacing cars, e.g. operated by traffic police? I.e. when you already know or can anticipate that there is a large jam building up, you bring in one pacing car on every lane at an appropriate low speed and everyone has to adjust, so the thing you mentioned won’t happen.

          • lightnsfw@reddthat.com
            0·
            1 year ago

            Nah, cops being on the highway is one of the big causes of traffic. Everyone slows down to the speed limit when they come up on a cop and many are too timid to pass at all. This causes a huge brake wave and fucks everything up. It’s why I don’t think speed limits should even be a thing or should at least be adjusted because most highways are so low that just about everyone ignores them (and is not harmed doing so) until law enforcement appears. If people want to go slower that’s fine but they need to keep right when they aren’t passing and everyone needs to leave plenty of space in front of them so that traffic is permeable enough that people can get to their exit without causing brake waves and absorb the “shock” when it is necessary for someone to hit their brakes.

          • thejoker954@lemmy.world
            0·
            1 year ago

            The problem with that is people would still do the same stupid shit behind the pace cars which would just cause the same issues.

            The only way traffic pace cars would work is with better fundamental training (and enforcement of that training [meaning cops would actually have to regularly ticket people for tailgating]).

            Especially here in the usa there are hardly any barriers to getting/keeping your license.

            There is a massive amount of drivers who either shouldn’t be on the road at all or with heavy restrictions like not allowed to drive at night, not allowed on the highway, not allowed to drive certain classes of cars (kinda like other countries do for motorcycles because there is zero reason for any joe schmoe to just be able to legally get behind the wheel of something like a supercar on public roads)

          • 5too@lemmy.worldEnglish
            0·
            1 year ago

            I feel like regular patrol cars might work like this already - who’s going to blow past a cop driving down the road?

          • timik_pipik@lemy.lol
            0·
            1 year ago

            Or we could just build trains and other alternatives to cars, which would end up cheaper, faster, safer, environmentally friendly, …but we have big oil.

            (Sry, I had to)

        • socsa@piefed.socialEnglish
          0·
          1 year ago

          Then leave another gap. There are finite idiots in the world, and you cannot actually go backwards.

        • kryptonianCodeMonkey@lemmy.world
          0·
          1 year ago

          You need to give even more space then so that them doing that doesnt make you slow down. People cutting in front of you also helps because those are the assholes causing the brake waves.

          • lemming741@lemmy.worldEnglish
            0·
            1 year ago

            At that point, you’re the guy doing 15 mph under the limit in the left lane.

            Please only attempt this in the right lane.

            • kryptonianCodeMonkey@lemmy.world
              0·
              1 year ago

              Everyone is doing 15+ under. We’re taking stop and go traffic. What are you talking about?

              Edit: Also the least effective place to do this is the right lane. The right lane can have traffic because exits are backup up onto the highway. The left lanes are the ones only getting backed up due to brake waves.

          • aesthelete@lemmy.world
            0·
            1 year ago

            I have adaptive cruise with a settable car length and increasing the gap length just makes the cars behind you act more deranged.

            I’ve found the only setting that doesn’t make everyone around me fly off the handle is the lowest (one car gap) setting.

            I also drive in the diamond lane on long trips and typically have my upper speed limit set well above what the person in front of me is driving.

            • Clent@lemmy.dbzer0.comEnglish
              0·
              1 year ago

              This is actually an argument for why these features should be mandatory. Traffic is caused by humans and their silly emotions. These types of self driving features with inter-communication would erase traffic jams.

        • AA5B@lemmy.world
          0·
          1 year ago

          Yeah, maybe I’m fooling myself but it really seems like hanging back more makes me have to do more sudden braking. Traffic seems smoothest when I’m close enough to discourage cut-ins …. Even if that means Im more at the mercy of traffic in front flowing down a bit

          But as a corollary, this is one of the reasons fewer lanes are sometimes better. A main road near me proved this out when they cut back from two lanes in each direction to one plus turn lanes. There’s no more jockeying for position, no more cut-in’s and you no longer have to protect your gap. Traffic is smooth and calm, and it improved accident statistics. Most importantly timing to get through that section is consistently better!

      • Omgpwnies@lemmy.worldEnglish
        0·
        1 year ago

        Adaptive cruise control FTW. Matches speed with the person ahead of me (up to the max that I set) and maintains a gap that I can specify. It starts slowing down long before I’d notice the gap closing if I were doing it myself, so the +/- acceleration is a lot smoother as a result.

        • kryptonianCodeMonkey@lemmy.world
          0·
          1 year ago

          So, I don’t know exactly how the adaptive cruise control works. But if it is slowing down and speeding up to maintain a specific distance, that does not fix things. The idea is to maintain a specific speed such that, as the people in front of you accelerate and brake, speed up and slow down, you have enough distance to not have to do that. You should essentially match their average speed with enough gap that their braking doesn’t put them close enough to your bumper that you have to slow down yourself. Normal cruise control would be better (except mine won’t set at speeds under, I think, 20mph) because your speed wont change. Adaptive cruise would make your drive safer, maybe, keeping you from being too close or failing to react to the change in traffic speeds, but I dont think it would solve the traffic issue itself.

          • aesthelete@lemmy.world
            0·
            1 year ago

            You aren’t solving traffic as an individual driver anyway. Sorry to burst everyone’s atomized bubble here but that’s complete nonsense.

            If you manually maintain a large gap in front of you, everyone behind you becomes complete weirdos.

            We could “solve traffic” by not requiring single occupant car drives to accomplish everything in our daily lives.

              • aesthelete@lemmy.world
                0·
                1 year ago

                You’re right of course, the reason traffic exists is because you, DancingBear, cannot be on every roadway in America at the same time.

                Seriously dude, have you ever been in traffic? I’m not talking about a small slowdown on a one, two lane, or even four lane road. I’m talking about sitting on the 5 or the 101 in any of the multiple times it becomes a parking lot daily.

                Manually maintaining a large gap in front of you is not solving that shit, and it’s frankly ridiculous to suggest that it will.

          • Omgpwnies@lemmy.worldEnglish
            0·
            1 year ago

            It’s not “locked” to a specific distance, it’s fairly elastic and the exact follow distance varies based on speed. So, if traffic slows down, it will gradually close the gap while also slowing down. The end result then is far less drastic speed changes.

      • HalifaxJones@lemmy.world
        0·
        1 year ago

        Californians te the worst drivers in the world because none of them understand this simple concept. Every day I’m driving, I give more than enough space in front of me for someone to cut me off and I don’t have to brake. It’s simple. However, I’m constantly getting people riding my ass. Switching around me. And being over all menaces just because I’m leaving a roper gap between myself and the car in front of me. It’s wild.

    • WhiteOakBayou@lemmy.world
      0·
      1 year ago

      In one of the Mission Impossible movies Tom Cruise is supposed to have a boring job no one will ask him about and the movie shows this by having the character talk about traffic patterns. I thought it was interesting information then and think it is interesting now.

        • blarghly@lemmy.worldEnglish
          0·
          1 year ago

          It’s kind of funny. The writers probably thought traffic pattern analysis is boring because everyone hates traffic. Actually traffic pattern analysis is interesting because everyone hates traffic.

      • marzhall@lemmy.world
        0·
        1 year ago

        Lmao I remember seeing this exact scene as a kid, thinking as he was talking “oh that sounds cool as fuck” and then only from how the scene played out realizing it was supposed to be a significantly boring concept

      • oddlyqueer@lemmy.ml
        0·
        1 year ago

        I couldn’t find the paper I was thinking of that described the phenomenon of traffic propagating as a pressure wave, but I did find this paper (new to me) that describes a model for simulating how congestion spreads in urban environments (as opposed to an isolated highway, which IIRC the paper that most people reference models). It does have the full text available though, and it looks like a good read and has references that should get you going on the history of congestion research.

        I am not an expert; I just found this with a few minutes of searching. If there are experts with better papers I’d be happy to hear from ya!

        https://www.nature.com/articles/s41467-020-15353-2.pdf

  • PhobosAnomaly@feddit.uk
    0·
    1 year ago

    A few years ago, I was bitching and moaning about a jam, and my pal just said “you’re not in traffic, you are traffic”.

    I know it’s nothing more than a cheeky soundbite but just reframing it like that and knowing I’m part of the problem rather than the exception has made me a lot calmer on slow moving roads.

    Plus it has encouraged me to either use public transport more, or just drive to a park-and-ride a mile or three out, and run the rest - facilities permitting of course.

    • Alcoholicorn@mander.xyz
      0·
      1 year ago

      Switch to a motorbike, then you can experience righteous anger at the handful of drivers slowing down hundreds of bikes and people in buses.

      • PhobosAnomaly@feddit.uk
        0·
        1 year ago

        Funnily enough, I’m planning on getting my licence at some point.

        I’ve no interest in motorbikes, I would just love to learn how to ride one safely.

        • Alcoholicorn@mander.xyz
          0·
          1 year ago

          I understood them as expensive toys, like an old Italian project car that’s fun to tool around in in nice weather, but when you need to get to work, you drive your car, but experiencing its role in SEA completely change my perspective. They can be cheap, boring, functional machines, with a suprisingly high capacity. that even a dog can perform basic maintenance on and keep running for decades, that work just fine in rain.

          • PhobosAnomaly@feddit.uk
            0·
            1 year ago

            Good shout.

            I live fairly rurally and the roads/drivers don’t really lend themselves to new riders.

            I think if I lived in a big town or city though, I’d absolutely pick up a chicken chaser and rattle about short distances on one, they seem to be perfect for that sort of use case.

            Plus, not that I’m a huge fan of tobacco advertising, bikes in the Rothmans livery look absolutely stunning to me.

    • bobs_monkey@lemmy.zip
      0·
      1 year ago

      I still lose it when I finally get to the front of the jam, and the only reason for said jam is because everyone is stopping to look at an accident on the OTHER SIDE OF THE HIGHWAY.

      • PhobosAnomaly@feddit.uk
        0·
        1 year ago

        Yeah, it’s frustrating.

        I’m not entirely sure what the rubberneckers want to see either. “Oh look, someone critically injured next to someone who is likely deceased”, because that isn’t a day ruiner at the best of times.

        Odd.

    • merc@sh.itjust.works
      0·
      1 year ago

      Basically one car breaking too much will make the following brake

      If the car in front of me started breaking, I’d definitely get out of the way.

  • RememberTheApollo_@lemmy.world
    0·
    1 year ago

    I find it’s the speeders, tailgaters, and the infuriating few that can’t seem to manage to go at the prevailing speed that cause the waves in traffic. The rest is structural - merges, construction, lane reductions, etc. The aforementioned all cause the slowdowns because they move quickly, traffic tends to follow, and end up constantly hitting their brakes riding the ass of the slower traffic. That starts a wave that ends up with traffic stopping when density is high enough.

    You can’t control others moving slower than you want, bitching about lane campers changes nothing, but managing a speed/spacing that allows little or no braking does wonders to keep things moving. If only people would bother to do so.

  • IninewCrow@lemmy.caEnglish
    0·
    1 year ago

    It’s all a mad rush of people trying to get to where they don’t want to be as fast as possible