5 ms·

this is satire right?

pj_mukh 3y ago
Are people this incredulous about public transit? I love autonomous cars, but its not scalable at all. Its obvious to me that public transit is the real future as the population grows.
- alooPotato 3y ago
  I think if you were building a city from scratch, it's arguable that self driving individual pods is the way to go for the most convenient AND most efficient door to door transport. Maybe you disagree, but its not important because we're not building cities from scratch. For existing city infra and politics that we have, I think self driving is def the best way to go. Suggesting that an individual should lobby their gov't to fix public transit seems like lower probability of success than voting with their wallet for longer self driving trips. Public transit isn't one of those things that can be incrementally fixed. Self driving cars on the other hand can incrementally make everything better, that's why its so appealing imo.
  - pj_mukh 3y ago
    I mean maybe if you're a small town and want to stay a small town. Large cities, should definitely drive most transportation away from personal vehicles/pods. Its simply a space/first principles issue [1]. The math seems 100x less scalable, simply because you hate being around other humans (in which case what are you doing in a big city anyway). [1]: https://farm9.staticflickr.com/8456/7999510360_8e46299621_z.jpg https://farm9.staticflickr.com/8456/7999510360_8e46299621_z....
    - alooPotato 3y ago
      I always see that image referenced and it's kind of BS. it assumes the buses are filled to the brim constantly but the cars only ever have 1 person it. It also doesn't take into account the transport to and from your door on both ends. It also doesn't consider the inefficiency in wait time. The ideal transport would be a cocoon just big enough for you to fit in that picks you up at your door and gets you to your exact destination with minimal energy overhead. I'd argue a self driving car is much closer to that ideal and we can iterate our way much easier to it than public transit.
      - pj_mukh 3y ago
        "It also doesn't take into account the transport to and from your door on both ends." This type of design is terrible for average health outcomes [1]. We should not be optimizing for this. Walking to the bus stop is a good outcome. We should optimize for better more frequent bus routes, but "door-to-door" is unnecessary and counter-effectual. The rest (iteration speed, filling a bus to the brim etc.) are just political problems just as intangible as "lets build better roads (public infrastructure) for autonomous cars", so we can put that aside. [1]: https://www.bu.edu/sph/news/articles/2023/us-neighborhood-walkability-influences-physical-activity-bmi-levels/ https://www.bu.edu/sph/news/articles/2023/us-neighborhood-wa...
        alooPotato 3y ago
        we don't have to couple exercise with transport. We don't say planes are bad because it reduces the number of cross country hiking trips people take. On filling a bus, I think its a fundamental shortcoming of having fixed routes that they'll never be as efficient as point to point transport, especially electrified transport. i'm not really making a political argument.
        pj_mukh 3y ago
        I agree with the second point but given as 80% of city transports post-covid is back to being fixed commutes along fixed routes, I'm happy optimizing that along transit ways. I don't really care what happens with the remaining 20%. Right now, nearly 100% of travel is with "personal cocoons", totally unnecessary (other than for political reasons) and creating immense downward pressure on health and social outcomes. In terms of levers the government has on health and social outcomes, transitway design is a big one, and it should use it. The fact that its done badly in America is a political problem, and if you have any political power it should be expended fixing that, not rolling back public transit.
        alooPotato 3y ago
        I think if these cocoons costed $2.50 a trip you might think differently. I think driverless cars + some iteration on the vehicles themselves gets us there (without subsidies!). People love the equity argument for public transit. Non personally owned, ubiquitous, driverless, cheap, efficient and most importantly convenient cocoons would increase equity a whole hell of a lot more than the traditional definition of public transit imo
  - bluGill 3y ago
    Pods are not the most efficient transport. It is simple geometry. Here is an expert in the field going into more detail. https://humantransit.org/2011/03/how-universal-is-transits-geometry.html https://humantransit.org/2011/03/how-universal-is-transits-g... (read the rest of this site too - lots of good stuff there)
    - alooPotato 3y ago
      I don't see anything in that article that actually states efficient transport. It's just a long winded way of saying that there are a lot of factors in network design. kind of a useless article imo
      - bluGill 3y ago
        Read it again and apply the geometry lessons to pods.
  - palata 3y ago
    > Self driving cars on the other hand can incrementally make everything better Except for energy consumption. If we were in a world were fossil fuels were unlimited and climate change was not a thing, maybe I would agree with you. But we are not. We need to get much more efficient with energy, and cars just can't do enough. Better accept it earlier than later and start building public transports wherever it's possible.
    - alooPotato 3y ago
      for city driving, electric vehicles are crazy efficient. the energy is negligble. basically all the driverless cars are EVs.
      - viraptor 3y ago
        That's an interesting claim, but have you got numbers to back it up, compared to bus networks which are also largely electric/hydrogen in most recent deployments?
        alooPotato 3y ago
        Google says it costs roughly 4 cents a mile to charge a tesla model 3. Most city rides are a couple of miles so its a really really small fraction of the cost of trip cost (even if you price at public transit prices)
        palata 3y ago
        Can we talk about energy, and not price? And compare the consumption of a Tesla Model 3 with the average number of passengers (< 1.5?) versus the consumption of electric public transit?
        alooPotato 3y ago
        Why? You can convert energy to cost and back - its all the same energy source for EVs vs public transit. Ultimately cost is what matters anyways. Who cares if the energy requirement of public transit vs an EV has a huge delta (spoiler: there isn't a huge delta in terms of energy per passenger mile). They are both super low and efficient.
  - snovv_crash 3y ago
    That sounds like hell. More areas should be walkable and bikeable. Motorized vehicles should be limited to minimal areas so that the rest is quiet, safe and accessible. European cities have it right here - underground transport and quiet walkable surface level.
    - alooPotato 3y ago
      i like tunnels too. Just put cars in them that can easily transition to surface streets for door to door. Bikeable/walkable cities are not an argument against quiet, cheap, ubiquitous, efficient driverless EVs.
- tanseydavid 3y ago
  Can you expand on that a little bit? What are the reasons that you believe that AVs are "not scalable at all?"
  - pj_mukh 3y ago
    This picture makes it clear, for the most part. Public transit is a pareto improvement on personal driving pods in terms of scalability. Especially for fixed commute routes. https://farm9.staticflickr.com/8456/7999510360_8e46299621_z.jpg https://farm9.staticflickr.com/8456/7999510360_8e46299621_z....
  - Tiktaalik 3y ago
    Regular cars aren't scalable at all. AVs are not any different than regular cars. In fact AV will increase the amount of cars on the road as more people that can currently not drive, such as children and the elderly, are now more likely to use a relatively low occupancy AV. So we can expect transit to get worse as AVs become prevalent. The only scenario where AV may scale better than cars is if we're talking about autonomous buses, and that will only perform better if they are given the other features of public transit, such as dedicated lanes, which require set routes, and we're pretty much just talking about public transit in general at this point.
deleted 3y ago
[deleted]

Are people this incredulous about public transit? I love autonomous cars, but its not scalable at all. Its obvious to me that public transit is the real future as the population grows.

alooPotato 3y ago
I think if you were building a city from scratch, it's arguable that self driving individual pods is the way to go for the most convenient AND most efficient door to door transport. Maybe you disagree, but its not important because we're not building cities from scratch. For existing city infra and politics that we have, I think self driving is def the best way to go. Suggesting that an individual should lobby their gov't to fix public transit seems like lower probability of success than voting with their wallet for longer self driving trips. Public transit isn't one of those things that can be incrementally fixed. Self driving cars on the other hand can incrementally make everything better, that's why its so appealing imo.
- pj_mukh 3y ago
  I mean maybe if you're a small town and want to stay a small town. Large cities, should definitely drive most transportation away from personal vehicles/pods. Its simply a space/first principles issue [1]. The math seems 100x less scalable, simply because you hate being around other humans (in which case what are you doing in a big city anyway). [1]: https://farm9.staticflickr.com/8456/7999510360_8e46299621_z.jpg https://farm9.staticflickr.com/8456/7999510360_8e46299621_z....
  - alooPotato 3y ago
    I always see that image referenced and it's kind of BS. it assumes the buses are filled to the brim constantly but the cars only ever have 1 person it. It also doesn't take into account the transport to and from your door on both ends. It also doesn't consider the inefficiency in wait time. The ideal transport would be a cocoon just big enough for you to fit in that picks you up at your door and gets you to your exact destination with minimal energy overhead. I'd argue a self driving car is much closer to that ideal and we can iterate our way much easier to it than public transit.
    - pj_mukh 3y ago
      "It also doesn't take into account the transport to and from your door on both ends." This type of design is terrible for average health outcomes [1]. We should not be optimizing for this. Walking to the bus stop is a good outcome. We should optimize for better more frequent bus routes, but "door-to-door" is unnecessary and counter-effectual. The rest (iteration speed, filling a bus to the brim etc.) are just political problems just as intangible as "lets build better roads (public infrastructure) for autonomous cars", so we can put that aside. [1]: https://www.bu.edu/sph/news/articles/2023/us-neighborhood-walkability-influences-physical-activity-bmi-levels/ https://www.bu.edu/sph/news/articles/2023/us-neighborhood-wa...
      - alooPotato 3y ago
        we don't have to couple exercise with transport. We don't say planes are bad because it reduces the number of cross country hiking trips people take. On filling a bus, I think its a fundamental shortcoming of having fixed routes that they'll never be as efficient as point to point transport, especially electrified transport. i'm not really making a political argument.
        pj_mukh 3y ago
        I agree with the second point but given as 80% of city transports post-covid is back to being fixed commutes along fixed routes, I'm happy optimizing that along transit ways. I don't really care what happens with the remaining 20%. Right now, nearly 100% of travel is with "personal cocoons", totally unnecessary (other than for political reasons) and creating immense downward pressure on health and social outcomes. In terms of levers the government has on health and social outcomes, transitway design is a big one, and it should use it. The fact that its done badly in America is a political problem, and if you have any political power it should be expended fixing that, not rolling back public transit.
        alooPotato 3y ago
        I think if these cocoons costed $2.50 a trip you might think differently. I think driverless cars + some iteration on the vehicles themselves gets us there (without subsidies!). People love the equity argument for public transit. Non personally owned, ubiquitous, driverless, cheap, efficient and most importantly convenient cocoons would increase equity a whole hell of a lot more than the traditional definition of public transit imo
- bluGill 3y ago
  Pods are not the most efficient transport. It is simple geometry. Here is an expert in the field going into more detail. https://humantransit.org/2011/03/how-universal-is-transits-geometry.html https://humantransit.org/2011/03/how-universal-is-transits-g... (read the rest of this site too - lots of good stuff there)
  - alooPotato 3y ago
    I don't see anything in that article that actually states efficient transport. It's just a long winded way of saying that there are a lot of factors in network design. kind of a useless article imo
    - bluGill 3y ago
      Read it again and apply the geometry lessons to pods.
- palata 3y ago
  > Self driving cars on the other hand can incrementally make everything better Except for energy consumption. If we were in a world were fossil fuels were unlimited and climate change was not a thing, maybe I would agree with you. But we are not. We need to get much more efficient with energy, and cars just can't do enough. Better accept it earlier than later and start building public transports wherever it's possible.
  - alooPotato 3y ago
    for city driving, electric vehicles are crazy efficient. the energy is negligble. basically all the driverless cars are EVs.
    - viraptor 3y ago
      That's an interesting claim, but have you got numbers to back it up, compared to bus networks which are also largely electric/hydrogen in most recent deployments?
      - alooPotato 3y ago
        Google says it costs roughly 4 cents a mile to charge a tesla model 3. Most city rides are a couple of miles so its a really really small fraction of the cost of trip cost (even if you price at public transit prices)
        palata 3y ago
        Can we talk about energy, and not price? And compare the consumption of a Tesla Model 3 with the average number of passengers (< 1.5?) versus the consumption of electric public transit?
        alooPotato 3y ago
        Why? You can convert energy to cost and back - its all the same energy source for EVs vs public transit. Ultimately cost is what matters anyways. Who cares if the energy requirement of public transit vs an EV has a huge delta (spoiler: there isn't a huge delta in terms of energy per passenger mile). They are both super low and efficient.
- snovv_crash 3y ago
  That sounds like hell. More areas should be walkable and bikeable. Motorized vehicles should be limited to minimal areas so that the rest is quiet, safe and accessible. European cities have it right here - underground transport and quiet walkable surface level.
  - alooPotato 3y ago
    i like tunnels too. Just put cars in them that can easily transition to surface streets for door to door. Bikeable/walkable cities are not an argument against quiet, cheap, ubiquitous, efficient driverless EVs.
tanseydavid 3y ago
Can you expand on that a little bit? What are the reasons that you believe that AVs are "not scalable at all?"
- pj_mukh 3y ago
  This picture makes it clear, for the most part. Public transit is a pareto improvement on personal driving pods in terms of scalability. Especially for fixed commute routes. https://farm9.staticflickr.com/8456/7999510360_8e46299621_z.jpg https://farm9.staticflickr.com/8456/7999510360_8e46299621_z....
- Tiktaalik 3y ago
  Regular cars aren't scalable at all. AVs are not any different than regular cars. In fact AV will increase the amount of cars on the road as more people that can currently not drive, such as children and the elderly, are now more likely to use a relatively low occupancy AV. So we can expect transit to get worse as AVs become prevalent. The only scenario where AV may scale better than cars is if we're talking about autonomous buses, and that will only perform better if they are given the other features of public transit, such as dedicated lanes, which require set routes, and we're pretty much just talking about public transit in general at this point.

deleted 3y ago

[deleted]