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Joined 2 years ago
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Cake day: June 11th, 2023

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  • wow, no.

    none of what you said is actually true.

    • “gridlock” happens in non-grid layouts too, the english name is just taken from american road patterns.
    • “show me…” no. YOU made a claim (that local information suffices, which is a VERY bold claim), so it’s on you to prove that local information suffices.
    • roads are absolutely NOT “like wires”; they are like pipes. which is why civil engineers commonly use fluid dynamics to simulate traffic.
    • the rest of what you said is irrelevant to everything else.

    seriously, if you make a claim contradicting both the very premise of the post, and common knowledge on the topic, then at least provide a source for that claim, lr explain WHY you think your claim is true.

    “all the information is there” is not enough information to verify the claim; it’s a wild guess without evidence to back it up.

    if shit where THAT simple, we’d have it figured out 50 years ago… it’s almost like this isn’t the simple problem you desperately want it to be…




  • I’m extremely sceptical about local data being enough to properly guide traffic…

    the problem is that intersections are connected.

    one intersection influences others down the line, wether that is by keeping back too much traffic, thereby unnecessarily restricting flow, or by letting too much traffic flow, thus creating blockages.

    you need a big picture approach, and you need historical data to estimate flow on any given day.

    neither can be done with local data.

    could you (slightly) improve traffic by using local traffic flow to determine signals? probably, sure.

    but in large systems, on metropolitan scales, that will inevitably lead to unforseen consequences that will probably probe impossible to solve with local solutions or will need to be handles by hard coded rules (think something like “on friday this light needs to be green for 30 sec and red for 15 sec, from 8-17h, except on holidays”) which just introduces insane amounts of maintenance…

    source: i used to do analysis on factory shop-floor-planning, which involves simulation of mathematically identical problems.

    things like assembly of parts that are dependant on other parts, all of which have different assembly speeds and locations, thus travel times, throughout the process. it gets incredibly complex, incredibly quickly, but it’s a lot of fun to solve, despite being math heavy! one exercise we did at uni, was re-creating the master’s thesis of my professor, which was about finding the optimal locations for snow plow depots containing road salt for an entire province, so, yeah, traffic analysis is largely the same thing math-wise, with a bit of added complexity due to human behavior.

    i can say, with certainty, that the data of just the local situation at any given node is not sufficient to optimize the entire system.

    you are right about real-time data being important to account for things like construction. that is actually a problem, but has little to do with the local data approach you suggested and can’t be solved by that local data approach either… it’s actually (probably) easier to solve with the big data approach!