Its not irrelevant. But driving becomes better the less people are taking cars. So, even for people who would never take public transport or something like that, its beneficial to invest in it.
Being able to take a car is a freedom, HAVING to take one isn't.
For several years (until Covid) I took the bus back and forth to work every day. So awesome.
It absolutely could not, here simply is not enough space for all those cars. A heavy rail metro line can carry up to 60 thousand passengers per hour per direction, which is the equivalent of a 30 lane highway.
Where did this stat come from? Caltrain fits about 650 and couldn’t possibly run once per 45 seconds to achieve that.
Heavy rail metro refers to a system like the NYC subway, whereas Caltrain would be classified as suburban rail.
A typical NYC subway train has 10 cars with room for 100 passengers each, so to achieve 60k p/h/d would require 60 second headways. This is shorter than the 90 second headways achieved in practice, though theoretically possible with automatic train control and platform screen doors. For a more realistic example, the cars have a crush loading of around 150 passengers, which means 60k p/h/d is possible with 90 second headways.
Suburban rail actually has a higher theoretical capacity than heavy rail metro, but this is achieved with very large trains rather than high frequency. Caltrain's new Stadler KISS EMUs will have a capacity of around 200 passengers and will operate in 7 car trains and 10 minute headways, so they will only achieve 8.4k p/h/d initially. However if we assume 300 passenger crush loading and 10 car trains, it could theoretically achieve 60k p/h/d with more reasonable 180 second headways.
Now running trains at crush load routinely doesn't make for a great passenger experience, but keep in mind that we are assuming a dual track railroad here. If you are willing to spare the extra 2 highway lanes' worth of right of way, you can lay quad track and run twice as many trains. Many NYC subway lines were built quad tracked so that express trains could pass locals, and Caltrain's ROW is more than wide enough to accommodate retrofitting another pair of tracks.
Either way, the exact vendor of the vehicle is a matter of trivia to the AV company, since the majority of the hard work goes into the software. Private companies have been servicing government contracts for decades, so I think it would happen if a government wanted it to.
That said, I paid a lot to live right by a good stop on a good line b/c I too like directness.
I love going directly from point A to B in a private space and I'm not ashamed to admit it. This provides value to my life in the form of comfort and convenience, factors that are so frequently waved away as irrelevant by anyone screaming "car culture".
However, it's admittedly obscene that for this privledge, my vehicle sits unused most of the time. I'd be more than happy to have a non-owned electric vehicle show up when I need it, take me to my destination, and then proceed to help someone else with their journey.