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Why would this be an issue with the driver? I don't mean that combatively; I really don't see it. It seems to me that any form of transit, autonomous or not,

by JadeNB 1y ago

Why would this be an issue with the driver? I don't mean that combatively; I really don't see it. It seems to me that any form of transit, autonomous or not, either runs on some sort of centrally controlled schedule subject to optimization, or can be summoned on demand, in which case it only works as long as not too many people use it (usually because of cost), or else it will lead to traffic congestion and worsen rather than improve traffic.

JumpCrisscross 1y ago
> Why would this be an issue with the driver? Drivers are the dominant operating cost of a bus system, and they’re typically paid regardless of ridership. That means you have a minimum ridership per driver required to offset their cost. Bus systems thus size the bus and route to ensure that minimum ridership. That, in turn, requires aggregating demand, i.e. forcing people to change the places and times of their transit to line up with the bus’s. Analogous to lift and drag, the more you force people to change their schedules, the more you lose potential demand to alternatives. If you don’t have a driver, you can make your transports as big or small as you’d like. In rare cases, they’ll be bus sized. But most busses either aren’t consistently full or lose a lot of potential riders because their schedules and stops are inconvenient. A fleet of smaller vehicles sops up that demand without hauling around a bunch of dead mass off rush hour.
- JadeNB 1y ago
  I'm not sure I agree with the conclusions, but I know that I haven't thought about it in detail and you obviously have. Thank you for the considered argument.
- bluGill 1y ago
  On demand is a bad thing - it means you can't know when the bus will arrive because sometimes it will take a detour to pick up someone else. For a bus to be useful you need assurance of when it will arrive so you can be on time but not too early. frequent buses are good because you shouldn't have to wait when you are ready to go. Fixed routes again mean you can plan on it.
  - JumpCrisscross 1y ago
    > On demand is a bad thing - it means you can't know when the bus will arrive You'd still have buses travel routes with fixed points they aim to be at on time. They just have more freedom between those points to deviate. Again, if you have one big bus this doesn't work. If you have lots of smaller ones, it does because not everyone on board will need to stop at every scheduled stop. (And if they do, you punt the detour to the next bus. Or better yet, spin up a new one from the garage. Mechanics you can't do with a fixed set of scheduled drivers.)
    - bluGill 1y ago
      If you punt that means someone isn't picked when expected and so is late. Even spinning a new one up means they are late. Geometry works againts you
- jltsiren 1y ago
  If most buses are consistently full, it means that you have too few buses or the level of service is poor outside peak hours. Transit systems are usually sized for peak demand. Because you are paying for the vehicles and the infrastructure anyway, the marginal cost of offering better service outside peak hours is low. Especially if the drivers receive monthly wages and have semi-reasonable shifts. And that means buses are far from being full most of the time.
  - JumpCrisscross 1y ago
    > Transit systems are usually sized for peak demand. Because you are paying for the vehicles and the infrastructure anyway, the marginal cost of offering better service outside peak hours is low. Especially if the drivers receive monthly wages and have semi-reasonable shifts Right. Now remove drivers from the equation. The ideal size for a bus goes down because you can effectively turn off parts of the bus outside peak hours. (By parking some of the fleet.) Moreover, you can induce new demand by adding (and moving) virtual stops wherever your customers are. Busses via rideshare doesn’t work with a driver; it does if you can spin up and down your fleet on a dime.
    - jltsiren 1y ago
      The dominant constraint is usually road capacity during peak hours. You need a certain number of large buses to handle that, and those buses are cheap to use outside peak hours. Ideal bus size may go down if peak demand also decreases. For example, if working from home becomes more common. Smaller buses may also become more viable when direct bus lines are replaced with rail lines and feeder buses.
      - JumpCrisscross 1y ago
        > dominant constraint is usually road capacity during peak hours Where are you getting this? I know of no transit system which would add more buses were there just less congestion…
        1y ago
- jeltz 1y ago
  A fleet of smaller vehicles will congest the roads during rush hour and will only work off peak.

by JadeNB 1y ago

JumpCrisscross 1y ago

> Why would this be an issue with the driver? Drivers are the dominant operating cost of a bus system, and they’re typically paid regardless of ridership. That means you have a minimum ridership per driver required to offset their cost. Bus systems thus size the bus and route to ensure that minimum ridership. That, in turn, requires aggregating demand, i.e. forcing people to change the places and times of their transit to line up with the bus’s. Analogous to lift and drag, the more you force people to change their schedules, the more you lose potential demand to alternatives. If you don’t have a driver, you can make your transports as big or small as you’d like. In rare cases, they’ll be bus sized. But most busses either aren’t consistently full or lose a lot of potential riders because their schedules and stops are inconvenient. A fleet of smaller vehicles sops up that demand without hauling around a bunch of dead mass off rush hour.

JadeNB 1y ago
I'm not sure I agree with the conclusions, but I know that I haven't thought about it in detail and you obviously have. Thank you for the considered argument.
bluGill 1y ago
On demand is a bad thing - it means you can't know when the bus will arrive because sometimes it will take a detour to pick up someone else. For a bus to be useful you need assurance of when it will arrive so you can be on time but not too early. frequent buses are good because you shouldn't have to wait when you are ready to go. Fixed routes again mean you can plan on it.
- JumpCrisscross 1y ago
  > On demand is a bad thing - it means you can't know when the bus will arrive You'd still have buses travel routes with fixed points they aim to be at on time. They just have more freedom between those points to deviate. Again, if you have one big bus this doesn't work. If you have lots of smaller ones, it does because not everyone on board will need to stop at every scheduled stop. (And if they do, you punt the detour to the next bus. Or better yet, spin up a new one from the garage. Mechanics you can't do with a fixed set of scheduled drivers.)
  - bluGill 1y ago
    If you punt that means someone isn't picked when expected and so is late. Even spinning a new one up means they are late. Geometry works againts you
jltsiren 1y ago
If most buses are consistently full, it means that you have too few buses or the level of service is poor outside peak hours. Transit systems are usually sized for peak demand. Because you are paying for the vehicles and the infrastructure anyway, the marginal cost of offering better service outside peak hours is low. Especially if the drivers receive monthly wages and have semi-reasonable shifts. And that means buses are far from being full most of the time.
- JumpCrisscross 1y ago
  > Transit systems are usually sized for peak demand. Because you are paying for the vehicles and the infrastructure anyway, the marginal cost of offering better service outside peak hours is low. Especially if the drivers receive monthly wages and have semi-reasonable shifts Right. Now remove drivers from the equation. The ideal size for a bus goes down because you can effectively turn off parts of the bus outside peak hours. (By parking some of the fleet.) Moreover, you can induce new demand by adding (and moving) virtual stops wherever your customers are. Busses via rideshare doesn’t work with a driver; it does if you can spin up and down your fleet on a dime.
  - jltsiren 1y ago
    The dominant constraint is usually road capacity during peak hours. You need a certain number of large buses to handle that, and those buses are cheap to use outside peak hours. Ideal bus size may go down if peak demand also decreases. For example, if working from home becomes more common. Smaller buses may also become more viable when direct bus lines are replaced with rail lines and feeder buses.
    - JumpCrisscross 1y ago
      > dominant constraint is usually road capacity during peak hours Where are you getting this? I know of no transit system which would add more buses were there just less congestion…
      - 1y ago
jeltz 1y ago
A fleet of smaller vehicles will congest the roads during rush hour and will only work off peak.