It seems like a much better plan is to separate drivers from other people more rigorously, and maybe mandate people drive the last-mile themselves (with AI help, obviously).
Similarly for long haul trucking applications - could the far left lane/carpool lane be safely dedicated to autonomous trucks during the hours of midnight-3AM with some bright blinking signs paid for by the autonomous trucking industry trade group?
There will still be the last-mile problem. Even if the "rail" is just cheap paint, you'll almost definitely never have 100% of roads painted, and paint wears over time or gets buried under snow etc.
Eventually we're looking for ways to add "more 9s" to the reliability and safety. A non-rail rail could add a bunch of 9s to well-trafficked routes.
As someone who lived in West LA for years and saw the new line come in, I'll stop you right there. Cities like LA, Mexico-City, San Jose, etc. are not well designed and trying to re-invent them is going to take one hell of an earthquake.
My brother lived off Geary for a few years and went to a few public meetings on the proposed subway line they want to put under it. He was interested in the idea, as the N-Judah is a methadone clinic (last he was there a few years ago, caveats apply). He never saw such NIMYism and such tight resistance by the property owners on Geary to any improvements whatsoever.
You don't just ease regulations or really do anything 'big' in any city. Palms must be greased, and if you do not it is a horrific process that takes at least a decade.
I'm not saying that you are wrong about the free market. However, my brother thought that the most fantastic thing about the new Star Trek movies (esp. the new Wrath of Khan) was not the warp-drive, nor the aliens, but the very tall building in SF. Even in 400 years, there is no way the planning boards would allow such things.
I used to ride a recumbent to UCLA now and then because I had a death wish, and it shocked me that it took 25 minutes and yet people spent 60 minutes in traffic in their cars every day just to get across the 405.
You're right, though, those cities are mostly lost causes, more for the attitudes present in them than the infrastructure. Doesn't mean we can't try to make any new ones better though.
Riding a recumbent to UCLA from 16th is hardcore. Everyone I knew that rode in west LA got hit at least once, if not more.
If there is anything to be nostalgic about the past over, its how civil engineering projects of such scale were a lot more feasible when the complexity of doing them was so much lower.
I invite anyone who buys into this sweeping generalization to walk a half mile in Las Vegas, NV; Tempe, AZ; Houston, TX; New Orleans, LA; or Tampa, FL in July or August.
Walking half a mile in 35 C (95 F) isn't an actual problem unless you have a medical condition or you are morbidly obese. For those very rare 40+ C (105+ F) days, throw an official midday siesta, or just shut everything down like for snow days.
Again with the hand waving as if this was a solved problem. Trust me - if you actually try to walk half a mile on a 90+ degree, high humidity day you will regret it. The issue isn't just infirmity - i.e. those prone to heat stroke or overweight, but one of comfort. If you actually try tooling around in Houston (for example) you'll end up soaked in sweat. It'll be worse if you're dressed for the office in long sleeves and slacks.
That's when you'll discover that more than the public need to adapt to public transportation uber alles. Can I use a shopping trolley for groceries? Sure. Can I cycle to work? No doubt. But what if your employer doesn't have showers available? Mine doesn't. I can't show up drenched in sweat looking like a wet rat and stinking all day of sweat. And that's exactly what'll happen if I ride the few miles I have to work. Even if I take a change of clothes to work I still have no place to shower and neither does anyone else unless they are health club members. There are many externalities you're just hand waving away. As someone who lives in this climate I assure you I'd love to see light rail everywhere but it just won't replace the last mile for people without drastic societal changes.
There's also the fact that bus and rail frequency needs to dramatically increase to entice riders and also accommodate them when they do come. Will people choose a 45 minute bus ride over a 15 minute drive? Particularly when on average you'll spend 7.5-10 minutes baking in the sun or lightly shaded by an un-airconditioned bus stop? Not unless forced to, no.
I mean, I'd love to see you medevac a gravely wounded person from the middle of Arctic tundra to a hospital 120 miles away on your feet.. except I wouldn't, because we have helicopters for a reason. We don't assume you should have to use a helicopter to get groceries though.
Self driving cars can't come quickly enough.
Unfortunately there are features of most US cities (lack of public interest, obesity, disability, low density, long commutes, weather) that block our adoption from approaching yours.
Cycling is great, I hope to get along in life without a car, but cars are still great to have as an option.