As a former tube-commuter and occasional BART-user, I'd wager that possibly a majority of the commuting trips in zone 1 are taking people from a mainline train station to somewhere, and then back in the evening. That option barely even exists in the Bay Area - indeed every time I look at how to use Caltrain from SFO I give up and rent a car instead.
I see. Yeah, unless it's rush hour, SF Bay Area public transit is nearly always slower than hiring a private car. I'm glad that it exists, but do wish the towns in the area cared enough to fix that.
every time I look at how to use Caltrain from SFO I give up and
rent a car instead.
BART really made a mess of transit to SFO, unfortunately. BART ridership never met projections so they played around quite a lot with service between Millbrae and SFO in effort to save money. For a while there was a Millbrae-SFO shuttle. For a while one line provided service during the day and one provided evening and weekend service. Even today only one of the two transbay lines that runs down the peninsula offers service to Millbrae and SFO.
Once you actually get to Millbrae you then get to deal with BART's whole NIH problem manifesting as a refusal (up until recently) to offer timed connections with Caltrain. And, of course, up until 2021 actually getting between the BART and Caltrain platforms involved a ton of walking.
As a former tube-commuter and occasional BART-user, I'd wager that possibly a majority of the commuting trips in zone 1 are taking people from a mainline train station to somewhere, and then back in the evening. That option barely even exists in the Bay Area - indeed every time I look at how to use Caltrain from SFO I give up and rent a car instead.