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Once you have self-driving, you don't _need_ buses. Large buses are fundamentally inefficient, they can never be made competitive compared to cars. And the mai

Once you have self-driving, you don't _need_ buses. Large buses are fundamentally inefficient, they can never be made competitive compared to cars. And the main source of inefficiency is the number of stops and fixed routes. You can easily solve all the transportation problems with mild car-pooling. Switching buses and personal cars to something like 8-person minibuses will result in less congestion and about 2-3 times faster commutes than the status quo. Only large dense hellscapes like Manhattan will be an exception.

rootusrootus 1y ago
Yeah I remember once doing the math, and it takes a relatively high level of ridership before a bus (or train) reaches the per-passenger efficiency of something like a Civic Hybrid carrying three passengers. We have a number of routes in my local area that I think could be more quickly and economically served by replacing the full size bus with something much smaller.
- bluGill 1y ago
  general rule of thumb is 5 passangers for a but to break even. Now a civic is a smaller car so it will be better, and you specified 3 passanges whes single occupant is by far more likely - even with those unrealistic assumption a typical bus will do well overall.
  - rootusrootus 1y ago
    I don't disagree, the typical use case isn't great for the car, this was just a thought experiment for what it would look like to use an efficient, reliable passenger car as an alternative to buses.
  - cyberax 1y ago
    > general rule of thumb is 5 passangers for a but to break even. "Break even" how? A bus has a road footprint of about 15 cars (it's more than the physical bus length because it also occupies the road during stops and is less maneuverable). 15 cars have the occupancy of about 25 people. > even with those unrealistic assumption a typical bus will do well overall. Nope. Buses absolutely fail in efficiency. They pollute WAY more than cars, and they have fundamental limitations like the frequency.
    - SoftTalker 1y ago
      They also contribute to pollution when they are stopped and you have 10 cars idling behind them because there's no room to pass. Repeat every 2 blocks.
    - dns_snek 1y ago
      > A bus has a road footprint of about 15 cars What's this supposed to mean? I can't even try to take it at face value, it's ridiculous. In bumper to bumper traffic they might take up 2 cars worth of footprint. At higher speeds it's even less as the footprint of each vehicle equals "vehicle length + following distance". At 30km/h (8.3 m/s) and minimal 1s following distance, the "footprint" of a 5m long car is 13m, and the footprint of a 12m long bus is 20m. At highway speeds their footprint is almost equivalent to cars. > it also occupies the road during stops I've never seen a bus block a busy city road. Either way this is an easily solvable problem stemming from poor design and lack of investment and not some inherent issue with this mode of transportation. > They pollute WAY more than cars Citation?
      - cyberax 1y ago
        > What's this supposed to mean? A single bus creates as much congestion as around 15 cars. It's a fairly well-known result in urban planning. You can verify by looking at the maximum lane throughput in vehicles per hour. > At higher speeds it's even less as the footprint of each vehicle equals "vehicle length + following distance". The commercial speed of buses in cities is around 10-15 mph. There are no "higher speeds" when talking about the city traffic. > I've never seen a bus block a busy city road. Either way this is an easily solvable problem stemming from poor design and lack of investment and not some inherent issue with this mode of transportation. I've seen buses blocking multiple cars for a traffic light cycle because buses take so much space. These days, it is apparently considered a feature in the pro-misery community... > Citation? For example: https://ourworldindata.org/travel-carbon-footprint https://ourworldindata.org/travel-carbon-footprint This is a very loaded topic. The average raw bus pollution is about 75g CO2e per kilometer, and a passenger EV is around 50g. However, these calculations neglect that a bus needs about 3.5 drivers per bus to be viable. And these drivers become by far the most polluting factor.
- QuadmasterXLII 1y ago
  carrying 3 passengers is doing all the work for you there

rootusrootus 1y ago

Yeah I remember once doing the math, and it takes a relatively high level of ridership before a bus (or train) reaches the per-passenger efficiency of something like a Civic Hybrid carrying three passengers. We have a number of routes in my local area that I think could be more quickly and economically served by replacing the full size bus with something much smaller.

bluGill 1y ago
general rule of thumb is 5 passangers for a but to break even. Now a civic is a smaller car so it will be better, and you specified 3 passanges whes single occupant is by far more likely - even with those unrealistic assumption a typical bus will do well overall.
- rootusrootus 1y ago
  I don't disagree, the typical use case isn't great for the car, this was just a thought experiment for what it would look like to use an efficient, reliable passenger car as an alternative to buses.
- cyberax 1y ago
  > general rule of thumb is 5 passangers for a but to break even. "Break even" how? A bus has a road footprint of about 15 cars (it's more than the physical bus length because it also occupies the road during stops and is less maneuverable). 15 cars have the occupancy of about 25 people. > even with those unrealistic assumption a typical bus will do well overall. Nope. Buses absolutely fail in efficiency. They pollute WAY more than cars, and they have fundamental limitations like the frequency.
  - SoftTalker 1y ago
    They also contribute to pollution when they are stopped and you have 10 cars idling behind them because there's no room to pass. Repeat every 2 blocks.
  - dns_snek 1y ago
    > A bus has a road footprint of about 15 cars What's this supposed to mean? I can't even try to take it at face value, it's ridiculous. In bumper to bumper traffic they might take up 2 cars worth of footprint. At higher speeds it's even less as the footprint of each vehicle equals "vehicle length + following distance". At 30km/h (8.3 m/s) and minimal 1s following distance, the "footprint" of a 5m long car is 13m, and the footprint of a 12m long bus is 20m. At highway speeds their footprint is almost equivalent to cars. > it also occupies the road during stops I've never seen a bus block a busy city road. Either way this is an easily solvable problem stemming from poor design and lack of investment and not some inherent issue with this mode of transportation. > They pollute WAY more than cars Citation?
    - cyberax 1y ago
      > What's this supposed to mean? A single bus creates as much congestion as around 15 cars. It's a fairly well-known result in urban planning. You can verify by looking at the maximum lane throughput in vehicles per hour. > At higher speeds it's even less as the footprint of each vehicle equals "vehicle length + following distance". The commercial speed of buses in cities is around 10-15 mph. There are no "higher speeds" when talking about the city traffic. > I've never seen a bus block a busy city road. Either way this is an easily solvable problem stemming from poor design and lack of investment and not some inherent issue with this mode of transportation. I've seen buses blocking multiple cars for a traffic light cycle because buses take so much space. These days, it is apparently considered a feature in the pro-misery community... > Citation? For example: https://ourworldindata.org/travel-carbon-footprint https://ourworldindata.org/travel-carbon-footprint This is a very loaded topic. The average raw bus pollution is about 75g CO2e per kilometer, and a passenger EV is around 50g. However, these calculations neglect that a bus needs about 3.5 drivers per bus to be viable. And these drivers become by far the most polluting factor.
QuadmasterXLII 1y ago
carrying 3 passengers is doing all the work for you there