The main difference of pumping water or gas through pipes is that the consumer does not care which part of the pumped product he gets. It's all the same. Delivering customer specific goods through pipes requires a very good management of the vehicle flow.
They're likely only running a single tunnel during very early testing in order to keep costs down.
Their idea is basically a cargo-carrying, miniature version of a rubber-tyre metro:
https://en.wikipedia.org/wiki/Rubber-tyred_metro
..which is a century old concept. Thus well-understood, as evidenced by the wikipedia article listing their benefits and downsides versus rail.
It's not clear to me that these tunnels will be sufficiently large.
Or you send a human down the line on a platform with wheels. The tunnel would have to be at least as high as those crates and at least twice as wide.
There are far bigger challenges here, like the absolutely massive cost of digging / boring the tunnel and trying to amortize that over what you're delivering. You have to move a fuckton of Big Macs to have this make financial sense, and your competitors include "a guy on an electric bike making tips who uses a few KWhr of electricity over an 8-10 hour shift."
It's really hard to compete against massively subsidized public infrastructure (roads and ICE vehicles) when you're not subsidized at all.
While I’m no fan of Musk and his management of Twitter has been a shit show, I must begrudgingly admit that he is damn good at building companies that produce real tangible hardware based products that require infrastructure
I would bet the most common situation is the stuck vehicle is just stalled and could be pushed and/or pulled by the car behind or in front of it.
For pulling, you might use an automatic coupler like railways use: https://en.wikipedia.org/wiki/Railway_coupling#Automatic_cou...
This.. has to be a joke? Surely they don't believe a "battery-powered autonomous vehicle" is more reliable than a pneumatic tube network?
ahem, a BEV has __a lot__ more failure points than just "empty battery"...
sending a complex machine down a tube will _always_ carry the risk of the complex machine reading down. pneumatic tube "vehicles" are simple, they can not break down.
I am not an expert, I don't know which one is better or more reliable, but your claim that once you monitor battery charge, everything is hunky dory is wrong.
I don't know how the factors compare, but tubes are not perfect.