You need to demonstrate that the cost of division {developing the coupling system, the extra materials for building with the coupling system, and having the two parts be unable to share physical mechanisms} will be less than the benefits of having smaller/cheaper tugs for the few people who really have a use for tugs.
And I think most people don’t really have enough of a use for tugs to overcome economics of scale for the near term. The majority of trips will take place with non-custom cabins:
The ordinary rider does not need custom cabins. Consider the amount of energy people put into meaningfully customising their homes/apartments in practice (not that much), then scale it down by 20x to account for the fact that people spend a lot less time in transit than they do at home. That’s how much people will care most of the time. I should examine some of the usecases though
unmanned delivery services only want tugs
people who use a wheelchair want a custom cabin they can just roll into
People who want to do morning routine stuff during commute want a cabin that supports that stuff? But wouldn’t the road movement interfere too much? I mean, have you ever stood in a bus? Imagine having to stay upright through all the shifting and jolting while showering, putting on pants, or eating a meal. If this were a thing, enough people would want it that they could just build a custom car entirely though.
Big visiting service station things?
Probably bad example: “mobile libraries”. A lot of these thingies seem less practical than just having a fixed building provide the service and moving people or goods between them.
Hm visiting remote-operated surgery theatres? That could be pretty badass
Storing your very own personal cabin, once arrived at your destination, will be an inconvenience. It would mean either sending it to a parking locker (which, if it’s in the urban center, you will have to pay a non-negligible amount to reside in), or all the way home again, to then have to wait for it to come out again when they’re ready to commute back. I think most people would stop bothering.
Hmm I was gonna say the tugs wouldn’t be that much cheaper than common single-occupant cars because they’d need to have enough mass to gain traction on the road, but it occurs to me, if you could have the tug go under the cabin to some extent, then jack it up a bit, it could use the weight of the cabin for traction, so assuming sufficiently dense batteries and motors (can we assume?) it could be pretty small. The heavier the cabin, the more traction it needs, but also the more traction it gets. That’s pretty neat.
A specialized cabin for your kid to drive to/from school alone, or for your toddler to drive to/from kindergarten alone. Robotaxis will definitely be used for this because it is super valuable to parents. But a small specialized cabin would be more economical than a standard (typical car size) cabin fitted with child seats.
Visiting dialysis station.
Specialized delivery cabins for particular types of cargo: refrigerated, extra suspension, stuff for transporting animals. We do this with trucks, but trucks are big because they’re optimized to need less human drivers per mass of cargo, and once that restriction is gone the disadvantages of big trucks should incentivize a move to smaller cargo vehicles.
I think these three are major enough that even if we stay with single vehicles, these use cases would merit development of specialized robotaxis to cover them, sooner or later. But a tug and cabin system gets there sooner.
In a car park? But they will be way more densely packed than cars in car parks, because no humans need access. The cabins get placed there and retrieved from there by autonomous engines.
I was thinking about people living in detached homes in residential neighborhoods, i.e. places where I would expect local politics to prevent car parks (‘parking lots’ in my colloquialisms) from being built at all.
You need to demonstrate that the cost of division {developing the coupling system, the extra materials for building with the coupling system, and having the two parts be unable to share physical mechanisms} will be less than the benefits of having smaller/cheaper tugs for the few people who really have a use for tugs.
And I think most people don’t really have enough of a use for tugs to overcome economics of scale for the near term. The majority of trips will take place with non-custom cabins:
The ordinary rider does not need custom cabins. Consider the amount of energy people put into meaningfully customising their homes/apartments in practice (not that much), then scale it down by 20x to account for the fact that people spend a lot less time in transit than they do at home. That’s how much people will care most of the time. I should examine some of the usecases though
unmanned delivery services only want tugs
people who use a wheelchair want a custom cabin they can just roll into
People who want to do morning routine stuff during commute want a cabin that supports that stuff? But wouldn’t the road movement interfere too much? I mean, have you ever stood in a bus? Imagine having to stay upright through all the shifting and jolting while showering, putting on pants, or eating a meal. If this were a thing, enough people would want it that they could just build a custom car entirely though.
Big visiting service station things?
Probably bad example: “mobile libraries”. A lot of these thingies seem less practical than just having a fixed building provide the service and moving people or goods between them.
Hm visiting remote-operated surgery theatres? That could be pretty badass
Storing your very own personal cabin, once arrived at your destination, will be an inconvenience. It would mean either sending it to a parking locker (which, if it’s in the urban center, you will have to pay a non-negligible amount to reside in), or all the way home again, to then have to wait for it to come out again when they’re ready to commute back. I think most people would stop bothering.
Hmm I was gonna say the tugs wouldn’t be that much cheaper than common single-occupant cars because they’d need to have enough mass to gain traction on the road, but it occurs to me, if you could have the tug go under the cabin to some extent, then jack it up a bit, it could use the weight of the cabin for traction, so assuming sufficiently dense batteries and motors (can we assume?) it could be pretty small. The heavier the cabin, the more traction it needs, but also the more traction it gets. That’s pretty neat.
For completeness, I should link a previous post about the economics of autonomous cars I did (which has comments, and links in turn to another post I did) https://www.lesswrong.com/posts/QDekD68bQiwuAJB8G/will-autonomous-cars-be-more-economical-efficient-as-shared
Here are more use cases.
A specialized cabin for your kid to drive to/from school alone, or for your toddler to drive to/from kindergarten alone. Robotaxis will definitely be used for this because it is super valuable to parents. But a small specialized cabin would be more economical than a standard (typical car size) cabin fitted with child seats.
Visiting dialysis station.
Specialized delivery cabins for particular types of cargo: refrigerated, extra suspension, stuff for transporting animals. We do this with trucks, but trucks are big because they’re optimized to need less human drivers per mass of cargo, and once that restriction is gone the disadvantages of big trucks should incentivize a move to smaller cargo vehicles.
I think these three are major enough that even if we stay with single vehicles, these use cases would merit development of specialized robotaxis to cover them, sooner or later. But a tug and cabin system gets there sooner.
Specialized cabins seem like they would hurt this idea – where would people store all of their cabins?
In a car park? But they will be way more densely packed than cars in car parks, because no humans need access. The cabins get placed there and retrieved from there by autonomous engines.
Good answer!
I was thinking about people living in detached homes in residential neighborhoods, i.e. places where I would expect local politics to prevent car parks (‘parking lots’ in my colloquialisms) from being built at all.