Ok, let me go through what I believe is the realistic way putting in local public transport in the suburban neighbourhoods in the US.
You first need a good bus network, every house should be with in a 10 min walk of a bus stop.
The local government then buys a few houses and plots of land, and build a metro station on them and runs a normal boring metro system under ground to either an existing metro system, or start building a metro system.
If you really want maglev you can allways install it later when the tech is mature enough.
As for the size of the tunnels, the sewer TBM you posted is way too small, there would be no space to place signals or other supporting infrastructure, it also severely limits the future tech that can be used on the sytem.
Little maglev pods, man. One seater (stander? layer?). They can string together in a train or go off individually. Switching stations no wider than three or four lanes, underground. You plug in your destination and hop in. Tubes small enough that they can also extend above ground and integrate into other transport. Would probably make people too claustrophobic to ever catch on though. If the feds could be like "yeah it's small, but we'll dig a tunnel right to your road and you can blast around safely in basically a straight line to wherever you want to go in a tiny fraction of the time driving would take, it would catch on.
Yeah your idea works, too. The last mile is the hard part. I agree we need a ten minute walk to a bus to make them useful. In America I don't know how that would be realistic for most places. I feel like most of America landwise, you're lucky if its a ten minute walk to the next house. So unless the busses are going up and down every road, that means at a minimum need an ebike maybe, but more likely just a car.
In my maglev solution, which I am making up as I go along, the switching and intersections and other key infrastructure for my maglevs are in large, modular blocks that get buried in a giant rectangle hole, maybe the size of a kids football field, and then we build a park and station right on top of it. The tubes can then go basically anywhere, connecting the modular blocks together. The roads are antiquated. The future of travel is sub terranean. Hopefully we don't also have to live down there.
I think it should be expanded and invested with bus-only highways, more routes, more stops, in places where that makes sense.
I am having trouble articulating it. Something about game theory and how mass transit gets increasingly inefficient the closer it gets to an individual's destination. And I just happen to think it's that last connection that, if it could be done efficiently, would really change up mass transit in America. It's fucked what happened to all the electric trolly ways and trams, and the railways, too. The rail trails everywhere are cool but now we have no trains. With my tubes, we get to keep the rail trails and can tube along right underneath them. I like PRT. And tubes.
While PRT is a fun concept to imagine, in reality it has a few of issues.
Low capacity, even if you were to run your pods together like trains, the capacity would still be far below that of even a bus, this is due to the limited seating in the pods and the required headway between the pods.
Security, a PRT pod is basically a movable locked room with a few seats in it, a young woman or child would be very vulnarable if they were alone with a sexual predator in the pod for a long ride. The dangers are not limited to women and children, but everyone is more vulnerable alone in a PRT pod with a stranger than on a bus with more strangers.
Manufacturer lock in, there are no general standards for PRT systems, meaning that any PRT system built will be locked in with a specific manufacturer, everything from track gauge and rail profile to signaling and control systems, to pods and security systems will need to be supplied by a single company, and it will be extremely hard to get another manufacturer to even agree to make replacements, let alone accomplish that. Busses and trains have standards to follow, but even if you have an odd track gauge or rail profile there are manufacturers who can deal with it, so you can get equipment from other manufacturers and be able to keep costs somewhat in check.
Bus stops on the main road(s), placed so everyone has a stop within a 15-20 minute walk.
Sort of agree with others suggesting getting rid of the neighborhoods in the first place, but sharing walls is hell. When the only way to speak confidentially in your own home is to whisper, it's impossible to wfh or have a telehealth appointment (or, worse, a teletherapy appointment).
That sounds more like a old/cheap construction problem than a shared walls problem. I live in an apartment with solid concrete walls built in the 80s and I never hear my neighbours unless they are full-on screaming, which I've only heard happen once.