Elon Musk is wrong: Robotaxis are stupid. We need standardized rented autonomous tugs to move customized owned unpowered wagons.

It's not either/or.

I no longer own a car, just use a ride share like car2go when I need to get somewhere. Also, I hate owning things. Renting what I need for when I need it and letting someone else deal with the nitty-gritty of maintenance frees my time and my mind. And I am not alone. Most corporate compute is rented. Most commercial space is rented. Most offices are rented. That most houses (in the US) are owned is an artifact of the way thing came to be. If land had no intrinsic value, and renting was a universally more economical option, then real estate ownership would drop dramatically over time.

that a single product, a single vehicle needs to do both the moving and the accommodation of the user

That's a good point. Short trips only need moving, and longer travel needs to include accommodation, though not necessarily of a house-type kind. So, there is some room for what you propose, but probably not for the daily commute, where splitting the tug from the cabin is not necessarily economical. Still, I can see that standardized tugs might be economically viable in some niche cases.

You combine some of the advantages of both approaches, but also some disadvantages:

• you need a parking spot
• you need to wait for the engine
• you need to be where your wagon is (or else have it delivered)
• you can be identified both through your wagon and your regular interaction with a centralized service

Upvoted for thinking beyond the obvious, but I don't think this will be popular or common. Accommodation and travel are different enough in character that trying to use the same container for both is going to be an ugly compromise. I travel because I _want_ to move to a different, shared, accommodation than my permanent too-large-to-move home.

Making housing pleasant and efficient, and making travel pleasant and efficient can both be done much more completely by not trying to combine them.

You may be right, but I read this more as an argument that we'll keep personal cars, not that we're rent out half of them. If we're sticking with personal wagons, isn't it easier to just own your own engine too? Electric engines are cheap and battery prices are going down.

It's possible that autonomy changes everything, but things somewhat like this have existed or been talked about:

• "Modular cars" have been attempted
• There have been various attempts at swapping the *battery* of an electric vehicle, including by Tesla. (As I understand it, obstacles include: the design advantages of making the battery a structural part of the car chassis; sophisticated battery management that involves "plumbing" the battery into the car's HVAC system). Swapping the battery seems a major move in this direction because the battery is a large amount of the *value* of an electric vehicle. (Conversely: while the vehicle is parked, connect the battery to the electrical grid, and the battery can earn money by arbitraging Watt-hours over time)
• Obviously, such things as RVs and Winnebagos and caravans exist
• Cargo containers (and truck/tractors/semitrailers) are something a bit like this, but for cargo

In my view, one big disadvantage of a privately-owned car is that that car's shape has to work for journeys in town, long road trips, vacations, etc, where actually you might prefer something small or shared in town (like a microcar, bicycle, or transit bus) and something roomier for a long journey (or bigger still if you're travelling with friends & family).

• I'm guessing robotaxis will come first, just because it's easier and requires less coordination between multiple parties, and then the demand for movable lockers will probably be satisfied by, well, movable containers that can go inside the robotaxis and use "AI" to follow people around when outside of the taxis, or maybe initially just containers that people can push around.
• If "take out your stuff every time you leave and check whether the previous user did every time you enter" turns out to be a big issue (don't people already do this all the time in regular taxis?) the robotaxis could have a narrow AI to scan and detect items that have been left behind, and remind you before you leave.
• "interference by users" can be handled the same way.
• Allergy to perfumes seems too rare to matter much, and could be handled by building a HEPA filter into the robotaxis.
• "A lot of complexity is removed from production, so these are much cheaper to build than robotaxis." But this is actually a "con" for the tugs/wagons model because this saving is more than made up for by the additional wagons that would have to be built.
• All in all it doesn't seem like your model offers enough additional value on top of the default scenario to overcome the additional coordination and other costs.

Maybe a bit off topic, but to me a future filled with robo-taxis, automated cashiers, drone delivery and other such things would feel kind of scary and alien. I've always lived in cities where you need constant human interaction to get by, and for myself I'd like things to stay that way or even more so.

My other comment was mostly critical but I just want to add that I really enjoy this kind of post. Any conversation about economics of future technology is fun imo.

Great thinking! However, the trouble is that this doesn't exclude non-autonomous motive sources. For example, why can't you just rent a tug driven by a person for your personal wagon? Additionally, there is a dichotomy of configurability vs availability of motion. You would seemingly have to wait on a tug to go anywhere. Cool thoughts though!

"There's a bit of a chicken and egg problem where you need to be sure the other part of the system will exist before you start producing your own side. But that seems solvable with sufficient clout."

I don't think clout is strictly needed (though it would definitely help)? You start with selling rich people 1 tug plus a bunch of different cabins for different purposes. Overnight trip? Mobile office? Date night? Pick up kids from school? Moderately well-off people follow suit but would like ownership to be less costly. Someone starts an uber-equivalent service. Some tug owners buy an extra and more generic cabin they don't use and use that as a taxi. The system gets entrenched enough that people can have their own cabins and trust a tug-on-demand will be available.

The biggest problems with cars are traffic congestion and parking space. I assume your wagons can be stacked on top of each other? If so, the human world would essentially become a giant warehouse where trucks move human-containers from one stack to another? Doesn't sound so much better than cities with robotaxis.

Modern cars have a swish, aerodynamic shape. Would a system composed of two coupled pieces get as good aerodynamics? I agree that there are some advantages to the proposed system, but there are also potential disadvantages.

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 [LW · GW]

Sounds good! I think many people would forego the luxury (parking spaces are expensive in cities & for a lot of people the transportation itself is enough), but I can imagine some part of the market being like this

Not wrong I think, as most others do as well it appears. But I think it better seen (as others note) as a good insight that has a place in the large mix rather than as some complete alternative to the current thoughts.

That seems to be a fairly normal trajectory for innovations -- they need to work at the edges. So the autonomous vehicles get started in places like mining where it's a more controlled and limited setting or factory floors. Slowly they can move to broader application, truck fleets (while I've not heard of them I would think something like patrol boats for customs would be something of a no brainer) and then into things like moving people via taxis.

I think the idea of separating the engine for the compartment just works into that a bit more slowly as the applications (an standards for coupling) get worked out. I would think the coupling aspect might be the area to start working on as that doesn't seem like it's on anyone's radar (though perhaps research in mining and rail yard areas might show something) but might dovetail well with existing plans - such as taxis. For instance, with urban travel (and perhaps even more so in suburban, not sure) it is likely that trips originating at one location, or even along a common path, could be more efficiently services even when the end destinations are vastly different with one taxi engine for part of the trip then one of more of the passenger containers disconnected at some point to where another taxi picks it up for the next led. Probably good logistic support could be found with rail management tools for starting points.