3 ms·

Taxis are not a sustainable public transportation system; they're supplemental, at best.

jeffbee 3y ago
On the other hand a self-driving bus route that comes much more frequently than any existing Muni line would be nice and cuts down on the main cost, which is operator labor.
- woodruffw 3y ago
  I can't claim to understand Muni's problems, but it occurs to me that an train is a much simpler problem (technically speaking) to solve than a self-driving bus. The former doesn't have to flow in and out of unstructured traffic, has only one degree of freedom, has well-deployed reference systems, etc. Maybe one day we'll have fully automated buses without any operators at all, but for the time being my understanding is that even self-driving cars still need a tender. The kind of bus volume (and corresponding idle drivers) you'd need to make up for a train's worth of commuters probably takes a heavy cut into any operator labor savings.
  - xnx 3y ago
    Waymo does have a support team, but it is not 1:1 with its vehicles. Trains a transportation system from a different era when there were peak commute times. They run at a fraction of their capacity now.
    - woodruffw 3y ago
      The trains seem busy enough here in NYC (too busy: they need to run more of them). I'm not aware of a city on Earth that's been able to obtain the kind of simultaneous density and livability that places like NYC have without mass transit. Comparatively dense cities without mass transit (like Manila) are choked in traffic; changing that traffic to electric traffic will make the air cleaner (good!) but will not address the latter problem.
      - xnx 3y ago
        NYC transit is great. Citibike and the ferry are my favorite parts. Crazy that you can't get a train from LaGuardia to Manhattan. $3.5 billion/mile is a lot to pay for new track! It's yet to be seen, but I'm hopeful that widespread use self driving vehicles of calm, quite, and safe transportation that flows like water.
        woodruffw 3y ago
        > $3.5 billion/mile is a lot to pay for new track! That's mostly paying for the tunnels, not the track. It shouldn't cost nearly that much, but it's not surprising that it isn't cheap either: the tunnels are being constructed under some of the densest and most expensive real estate in the world, and the resulting stations are significantly larger than others in the system. And note: if you think that's expensive, you won't believe what it costs to repair highways in NYC[1]. [1]: https://ny1.com/nyc/brooklyn/news/2020/02/25/city-council-floats-two-repair-plans-for-the-bqe https://ny1.com/nyc/brooklyn/news/2020/02/25/city-council-fl...
  - farzinadil 3y ago
    Unfortunately, MUNI is not grade separated and the Muni trains do have to interface with traffic. Still easier than cars but similar challenges. And unlike the private industry in SF, the public agencies seem allergic to technology.
xnx 3y ago
What's not sustainable? Low infrastructure cost because they don't use expensive and custom rails. Infinitely flexible because they connect any two points on any schedule. Low operating cost because there are no human operators and they are mainly based on commodity vehicles. Rides could be subsidized for low income and would be a huge timesaver for things like grocery trips. They don't currently work well for extreme surge like concerts and sporting events, but there could still be custom shuttle buses for that. The technology isn't here yet, and it sucks that only one vendor is close, but it seems very promising.
- woodruffw 3y ago
  That "infinite flexibility" is the road network's greatest advantage and greatest curse: you can connect any two points because the network is built for individuals in private vehicles, not mass movements. Self-driving cars may make our highways more efficient, but they can't change the basic fact that a road with individual-sized cars on it carries far fewer people per square foot than mass transit does. (And note: we currently subsidize the hell out of our road network, in a way that's far less obvious to the public mind than our comparatively light subsidization of mass transit. It remains to be seen whether the average car trip is actually net cheaper.)
  - xnx 3y ago
    That's a good reminder that there are a lot of hidden subsidies for roads too. I imagine that we'll always have roads, but rails systems are optional, so the cost of roads is a given. Widespread use of self-driving vehicles should dramatically reduce the amount of lanes that need to be maintained though. I'm familiar with the arguments about rail capacity vs cars, but I live by main road and train lines. The road is in use 24 hours a day, and the rails are mainly idle. My dream scenario is self-driving vehicles become ubiquitous and we replace all commuter rails systems with foot and bike paths.
    - woodruffw 3y ago
      > The road is in use 24 hours a day, and the rails are mainly idle. This is a measurement error: you might see 300 cars in an hour and only two trains, but those 300 cars are carrying 600 people while the trains are carrying 1500 each. The road appears busy and the rail system idle, but the exact opposite is true in terms of volume of people moved. (It could also be true that the train system isn't well utilized in your area, but the fundamental point about scale and measurement is the same.) As others have pointed out elsewhere in the thread, the main cost of mass transit is actually labor, not the rails (or even trains) themselves. The US is somewhat behind the times in realizing this; just about everywhere I've been in Europe has healthy mass transit systems that run cheaper and more reliably due to increased automation.

On the other hand a self-driving bus route that comes much more frequently than any existing Muni line would be nice and cuts down on the main cost, which is operator labor.

woodruffw 3y ago
I can't claim to understand Muni's problems, but it occurs to me that an train is a much simpler problem (technically speaking) to solve than a self-driving bus. The former doesn't have to flow in and out of unstructured traffic, has only one degree of freedom, has well-deployed reference systems, etc. Maybe one day we'll have fully automated buses without any operators at all, but for the time being my understanding is that even self-driving cars still need a tender. The kind of bus volume (and corresponding idle drivers) you'd need to make up for a train's worth of commuters probably takes a heavy cut into any operator labor savings.
- xnx 3y ago
  Waymo does have a support team, but it is not 1:1 with its vehicles. Trains a transportation system from a different era when there were peak commute times. They run at a fraction of their capacity now.
  - woodruffw 3y ago
    The trains seem busy enough here in NYC (too busy: they need to run more of them). I'm not aware of a city on Earth that's been able to obtain the kind of simultaneous density and livability that places like NYC have without mass transit. Comparatively dense cities without mass transit (like Manila) are choked in traffic; changing that traffic to electric traffic will make the air cleaner (good!) but will not address the latter problem.
    - xnx 3y ago
      NYC transit is great. Citibike and the ferry are my favorite parts. Crazy that you can't get a train from LaGuardia to Manhattan. $3.5 billion/mile is a lot to pay for new track! It's yet to be seen, but I'm hopeful that widespread use self driving vehicles of calm, quite, and safe transportation that flows like water.
      - woodruffw 3y ago
        > $3.5 billion/mile is a lot to pay for new track! That's mostly paying for the tunnels, not the track. It shouldn't cost nearly that much, but it's not surprising that it isn't cheap either: the tunnels are being constructed under some of the densest and most expensive real estate in the world, and the resulting stations are significantly larger than others in the system. And note: if you think that's expensive, you won't believe what it costs to repair highways in NYC[1]. [1]: https://ny1.com/nyc/brooklyn/news/2020/02/25/city-council-floats-two-repair-plans-for-the-bqe https://ny1.com/nyc/brooklyn/news/2020/02/25/city-council-fl...
- farzinadil 3y ago
  Unfortunately, MUNI is not grade separated and the Muni trains do have to interface with traffic. Still easier than cars but similar challenges. And unlike the private industry in SF, the public agencies seem allergic to technology.

xnx 3y ago

What's not sustainable? Low infrastructure cost because they don't use expensive and custom rails. Infinitely flexible because they connect any two points on any schedule. Low operating cost because there are no human operators and they are mainly based on commodity vehicles. Rides could be subsidized for low income and would be a huge timesaver for things like grocery trips. They don't currently work well for extreme surge like concerts and sporting events, but there could still be custom shuttle buses for that. The technology isn't here yet, and it sucks that only one vendor is close, but it seems very promising.

woodruffw 3y ago
That "infinite flexibility" is the road network's greatest advantage and greatest curse: you can connect any two points because the network is built for individuals in private vehicles, not mass movements. Self-driving cars may make our highways more efficient, but they can't change the basic fact that a road with individual-sized cars on it carries far fewer people per square foot than mass transit does. (And note: we currently subsidize the hell out of our road network, in a way that's far less obvious to the public mind than our comparatively light subsidization of mass transit. It remains to be seen whether the average car trip is actually net cheaper.)
- xnx 3y ago
  That's a good reminder that there are a lot of hidden subsidies for roads too. I imagine that we'll always have roads, but rails systems are optional, so the cost of roads is a given. Widespread use of self-driving vehicles should dramatically reduce the amount of lanes that need to be maintained though. I'm familiar with the arguments about rail capacity vs cars, but I live by main road and train lines. The road is in use 24 hours a day, and the rails are mainly idle. My dream scenario is self-driving vehicles become ubiquitous and we replace all commuter rails systems with foot and bike paths.
  - woodruffw 3y ago
    > The road is in use 24 hours a day, and the rails are mainly idle. This is a measurement error: you might see 300 cars in an hour and only two trains, but those 300 cars are carrying 600 people while the trains are carrying 1500 each. The road appears busy and the rail system idle, but the exact opposite is true in terms of volume of people moved. (It could also be true that the train system isn't well utilized in your area, but the fundamental point about scale and measurement is the same.) As others have pointed out elsewhere in the thread, the main cost of mass transit is actually labor, not the rails (or even trains) themselves. The US is somewhat behind the times in realizing this; just about everywhere I've been in Europe has healthy mass transit systems that run cheaper and more reliably due to increased automation.