• socsa@piefed.social
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    20 hours ago

    Hey I studied this in grad school for a bit, and it really is just “someone does some dumb shit which leads to a cascading wave of additional people doing dumb shit which propagates backwards for miles.” Basically when the offered load is getting close to the maximum load, all it takes is one person aggressively changing lanes to throw that section of highway into gridlock, and it will remain that way until the total integrated traffic flux across that incident boundary again falls below the critical offered load inflection point.

    Basically, pick a lane and just stay in it. Maintain proper following distance. Counterintuitively, the following distance should be for the speed you want to drive, so even in traffic it should be like 5+ car lengths even though you are going slow. This is because it reduces the offered load, and once that number falls below the critical point, speeds will increase again. Bumper to bumper traffic basically prevents that from happening because it dampens the ability for a “speedup” wave to propagate.

    Of course this is all impossible for humans. All it takes is a few idiots to throw off the balance.

    • LemmyZed@lemmy.ca
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      5 hours ago

      So basically: 1. Put people in public transport away from the steering wheel, 2) scale back cars use.

    • Takios@discuss.tchncs.de
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      19 hours ago

      so even in traffic it should be like 5+ car lengths even though you are going slow.

      Other drivers: “It’s free real estate”

      • Corn@lemmy.ml
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        12 hours ago

        Secret is to play the game next to a semi. Some semis kinda do it too by engine braking as they see the wave approaching instead of waiting until theyre close to even slow

    • JargonWagon@lemmy.world
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      12 hours ago

      Yep! All it takes is one person braking, and then the person behind braking, then the person behind them, and eith each braking the overall speed slows down more and more. It creates a wave of traffic. The wave passes through. The starting point I think moves back further and further.

      I think about it a lot while I sit in traffic.

      • mechoman444@lemmy.world
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        11 hours ago

        I think the issue is more or less slow drivers. One asshole is going 60 in a 70 in the left lane which caused people to pass them which in turn cause the cascade from the maneuvering around the slow person.

        Slow drivers are far more dangerous than people don’t 10 15 over the speed limit.

          • Corn@lemmy.ml
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            5 hours ago

            If people pass quickly, then get out of the left lane, nobody needs to brake and start a compression wave

    • ftbd@feddit.org
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      9 hours ago

      “Pick a lane and stay in it” leads to slow drivers blocking the left lane, no?

      • seralth@lemmy.world
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        7 hours ago

        You have demonstrated why fundamentally humans suck at driving and this problem is unsolvable.

        Not because you asked the question but because it’s not intuitive why.

        So long as this has to be explained to anyone it can’t be solved.

        • ftbd@feddit.org
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          7 hours ago

          I’m genuinely curious: are there adverse effects to an arrangement where the right lane is used by large trucks going 90-100 kph, middle lanes used for normal traffic going 120-130 kph and the left lane kept open for faster traffic? As far as I understand, these issues arise when cars go back and forth between lanes all the time, or when cars go slower than the ones behind them without an open lane to overtake them. If you pick a lane and stay in it, you might cause the second issue