Getting tech employees off cars doesn't need self-driving cars. Google is perfectly happy to have shuttle buses, and pay for them, provided that housing is sufficiently dense, and there is a place where the buses can legally pick up and drop off employees.
Probably the biggest problem with using mass transit is latency; having to wait around doing nothing until your transport arrives. It's a constraint on your schedule and adds a certain amount of stress to your day. And if your desired departure or arrival time don't coincide closely with the schedule, you're going to waste a bunch of time even if the transport is quick.
Subways solve this problem by running every couple of minutes. Buses generally don't solve this problem well because traffic and alighting / loading delays cause them to bunch up. But on-demand self-driving cars can solve this problem, as long as there are enough of them close enough.
Having ridden the Google buses for 6 years, I can tell you this generally wasn't a problem. They were almost always on schedule (I'd say 95% with 2-3 minutes of planned departure) and never bunched up. You didn't really have a latency problem, because you knew exactly when you needed to be at the stop, and the bus would be there right on time.
One bus replaces probably 150 car trips a day (assuming it makes ~3 runs, partially full. If you assume similar capacity utilization on cars (3 passengers), it would take ~50 car trips to replace those 3 runs, effectively putting 17 cars on the road for every bus currently in operation.
Bay Area buses don't solve this problem but many bus systems do. Compared to an effective bus network, Bay Area buses suffer from:
* Short distance between stops (due to low housing density).
* Traffic due to lack of bus lanes.
* Long time spent at stops due to cash payments and/or single door entry, rather than proof of payment or tap on stations at every door, no cash allowed.
* Inaccurate/nonexistent realtime updates.
A bus every 30 minutes isn't a big deal compared to SF/Bay Area travel times, but only if I can rely on a timetable/GPS to arrive at the stop 2 minutes before departure and be confident with a scheduled arrival 2 minutes before my appointment.
Low density means that there are less people per km within walking distance of a bus stop which means you pick up less people. So it’s less efficient in that way. High density means at each stop there is much higher amount of people who live near the stop.
How do you think that means shorter distances between stops for lower density? You pick up less people per stop, but it's less also people over a given distance, so it doesn't imply stopping more frequently.
"Short distance between stops (due to low housing density)"
If anything, you have it backwards. In most of SF, places with high housing density (e.g. Van Ness) have their stops closer together than places with far lower density (e.g. Geary in the outer Richmond).
I suspect (but do not know for sure) that this is done on the theory that dense neighborhoods require more granular transit access.
I have noticed that waiting around on the subway platform or at the bus stop is way more stressful than sitting on the subway or the bus, even if the subway/bus is just stuck for some incomprehensible reason and showing no sign of progress towards my destination.
This leads me to suspect that the stress of waiting for public transit is largely incidental and could be reduced by better station design, without having to make any (difficult, expensive) improvements to service frequency and reliability.
> Subways solve this problem by running every couple of minutes.
Similarly, in many transport corridors intercity rail runs several times an hour (not so much in the US) and shuttle flights run every hour or two. Which are also sufficient in those contexts, in that it becomes reasonable to show up at the station/airport without checking the timetable.
more housing = more residents = more local tax income
That's the formula San Jose followed for two generations and is exactly why it's less successful than its neighbors, who pursued industrial development plus "big box" retail (both of which provide a better local tax base). Sunnyvale, Mountain View, etc. used San Jose as a "bedroom community" and instead welcomed a more industrial base.