Highway spending increased by 90% in 2021. This is one of many reasons why car traffic is growing faster than population growth.

  • Farid@startrek.website
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    3 months ago

    Doesn’t Lyft work sorta like that? Idk, it doesn’t operate in my country, but from what I’ve seen online, it’s several strangers sharing one ride.

    But after giving it more thought, I tend to agree with you on this. Except… After posting my comment I got curious and decided to calculate the efficiency of cars vs busses. I always assumed that they were way more efficient than cars (cause lugging around 2 tons of steel just to move 1 or a couple 70kg hairlines apes is stupid). But it turns out that busses only win if we compare it to cars with only one passengers. So basically, at half load, both are about equally efficient (about 10%). And on average a bus is only half full. Turns out, busses are really heavy… there’s of course the density, and busses win if you give each passenger their own car, but if we pack cars fully, they will be significantly more efficient. Not to mention if you use smaller European cars that carry basically their own weight in passengers.

    So my conclusion is, to maximize efficiency in the future we should try to implement a system of highly packed smaller sized transportation devices.

    Edit: I did some more calculations and now disagree with my own conclusion. Busses still win even when cars are reasonable utilized, not to mention the usual utilization, which is 1.2 passengers.

    More details in this comment.

    • AA5B@lemmy.world
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      3 months ago

      There are multiple levels of efficiency or benefits here for the bus over the car

      • no worries about driving or parking
      • all incomes, ages and skill levels
      • can handle groups
      • can handle more people, such as at rush
      • don’t require street parking
      • don’t require parking lots
      • don’t require as many garages, gas stations, repair shops
      • timbuck2themoon@sh.itjust.works
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        3 months ago

        Thank you. You succinctly summarized what I was going to post. The cost to subsidize cars far outweighs whatever theoretical efficiency gains just from packing cars more densely.

      • Farid@startrek.website
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        3 months ago

        I already crossed out the statement you’re referring to and added and edit, but I was talking strictly about weight carrying efficiency. As in, how much useful work is done compared to carried weight. You still make some fair points that I didn’t consider though.

    • daltotron
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      3 months ago

      Doesn’t Lyft work sorta like that?

      I’ve only ever heard of lyft being a normal taxi service where people just use their own cars they already own. Also, I dunno where you’re getting your numbers for the calculation you’re doing, that would probably be something good to include. You could say the same for everything I write, I guess, but none of my criticisms much have to do with the numbers, except for this: I dunno what “smaller european cars” you’re using. Most cars nowadays are like, 2 tons or so at the least, probably more, and you could maybe get one ton of human body weight, at the most, if you had several 250 pound chucks riding around in one car, which I don’t really imagine to be the case normally at all.

      There’s also an efficiency created by the “inefficient” route planning of the bus. By having something that travels in a loop, rather than having every individual travel to every individual point, we’re trading some amount of efficiency in terms of total time spent by everyone (theoretically, but this time is probably eaten up by increased amounts of car traffic in reality), and we’re trading that for a slight increase in the amount of foot traffic that people are collectively engaging in, which is probably a good thing. So that’s a total decrease in curb weight as a factor of total travel time, which is a decrease in road maintenance.

      You’re also probably looking at a massive decrease in mechanical maintenance for buses compared to cars, using one big engine, set of brakes, A/C systems, etc, rather than like 15-20 smaller non-standardized sets, and maintenance costs for the specific roads you’re traveling on via bus means you can engineer in less maintenance over time compared to a more spread out system.

      Density is also a pretty big consideration, because real estate downtown, i.e. the location most people are going to want to go, is at a high premium, both for people and for the city/state’s tax base. High density has the capacity to provide a sustainable tax base for the cost of providing utilities and maintenance by the city… Unless you park the series of autonomous cars all in some huge superstructure outside of town, and then basically just merge them straight into the highway, where you’d still have to overbuild and deal with a massive amount of car infrastructure (more than just the space you’d save on all this parking, since you could just have a couple pickup and dropoff spaces, if that, compared to all this other parking taken up downtown). I can’t really see it working out, and even at the normal densities we’d be looking at, I’d struggle to come up with a way by which it’s more efficient overall.

      There’s also other types of buses, if we’re just talking about emissions efficiency, or energy efficiency. Obviously an overhead electrified bus is probably the most desirable, just behind a tram or a streetcar or whatever. Then you have the weird stupid hybrid battery overhead-electrified buses that I hate, and then probably all your natural gas buses and diesel buses and whatnot, and then your pure battery buses.

      If we’re talking about autonomous vehicles, then we’re kind of also sidestepping all these questions about like, the scalability of the AI for this, and the computing power we’d have to use on that, constantly. We’d have to deal with the traveling mailman problem on a near constant basis, something which public transport can mostly sidestep by assuming passengers will come to it, and that public transit will be of a high enough density to create desirable locations simply by stopping there. We have all the pedestrian and cyclist traffic conflicts which we’d encounter, or else have to segregate from these cars entirely (something normal traffic already struggles to do adequately). And if we’re segregating the traffic entirely with a large amount of infrastructure, which definitely makes this much more achievable and easier, if still not easy, I think it makes more sense from a top down maintenance perspective to just go for trams or streetcars, or subways, or something like that.

      I think the only real way in which I can cook up a reason this might be done, is because it’s outsourcing costs onto the public, and onto the state. Road maintenance can be done by the city, or state. Probably, this would mean that the autonomous vehicles would not be segregated, which means it’s less of a good idea, which I believe, is the primary reason it hasn’t been done. Then, the taxi service could basically make a bunch of money on their highly necessary transportation, which they have created a large need for, simply by existing and demanding a large amount of infrastructure by existing.

      Use bicycles, e-bikes, and walking for individual pedestrian point to point travel. Fuck all the bullshit excuses people give about how, oh no it’s too hot out, too rainy, too hilly, what do I do with this cargo that’s not large or consistently arriving or departing enough to be loaded by a freight train, or by a professional truck, but isn’t so small that I can carry it, what do I do with all my kids, etc… Use cars sparingly enough to fill the very minor amount of gaps that can’t be bridged by bikes, cycling, and public transit, as a method of last resort. Mostly for people that would maybe need to live out in the boonies, like park rangers, maybe. Actual farms, not the stupid rich people playtime “ranches”, and industrial locations, they usually have a large enough cargo haul to justify a small freight train, or a large truck taking a small route to a freight yard.

      • Farid@startrek.website
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        3 months ago

        I dunno where you’re getting your numbers for the calculation you’re doing, that would probably be something good to include

        Absolutely fair. In fact, since yesterday night I tried to do more variations of my calculations for different types and now I, at least, heavily doubt my own conclusions and, at most, disagree with my conclusions entirely. Especially taking into consideration some of the aspects that people like you mentioned. But here’s my approach. When I was saying “efficiency” I specifically meant percentage of useful work done relative to weight (I know it’s not a be-all, end-all metric, but that’s what I chose). For example, a 2 ton car carrying one 70kg person has efficiency rating of:
        (70 kg / 2,070 kg) * 100 = ~3.38%
        Then I did these calculations for 1, 3 and 5 passengers, which makes 3.38%, 9.50% and 14.89% respectively. Then I took a random bus (curb weight = 12000 kg, max capacity 40 passengers), and repeated the calculations for 1 passenger, half and full occupancies. That came out to 0.58%, 10.45% and 18.92% respectively. Seeing that at half occupancy, cars are basically as efficient as busses, and knowing that on average busses are not even half-loaded (around 40%) I concluded that cars are in fact very efficient, given that you use them properly.
        But of course that isn’t the whole picture. Some issues with my numbers that I found:

        • average car is much lighter than 2000 kg (regular sedans are about 1500 kg, and a typical European car is around 1100 kg)
        • busses at that weigh actually have much more occupancy
        • it’s unfair to compare half occupancy, because statistically cars have 1.2 passengers on average.

        Taking these things into account, I (mostly Claude) made this calculator. It even has rough numbers for certain cars and bus types. Using that calculator I can clearly see, that busses win, even when lighter cars are reasonably utilized.

        talking about autonomous vehicles

        This was a sci-fi hypothetical anyway, even optimistically, I don’t think we will have truly self-driving cars for another 5-10 years. I agree with a lot of what you said, but we can’t really apply today’s approach to that future sci-fi scenario. For example, if we have a swarm of hive-mind public cars that anticipate each other’s moves, then those potentially could be way more efficient than route based traffic. But I don’t wanna fixate on the hypotheticals.

        Regarding your last paragraph, I don’t own a car, mostly walk and use trams. But I live in Europe, and here in Warsaw, we don’t really have a car problem. Sure, the work commute hours are a bit loaded, but otherwise, public transport is really good and a car is barely needed. So yes, until further notice, avoid cars if possible.

        Thank you for such a lengthy and detailed response!