Here’s a very interesting post from a blog in Houston, a metro area that has even greater problems with auto-dependence and transit fragmentation than the Bay Area. The post describes a coordinated intermodal system used in a multi-centric region of Germany that has four different types of transit used for different needs, including inter-city travel, commuter travel, and city travel. The pieces are designed to knit together, minimizing transfers and supporting easy transfers from mode to mode.
The kicker — the region in question covers the same amount of geographical area as Houston, which covers over 10,000 square miles in 10 counties. The Bay Area is somewhat smaller, about 7,000 square miles in 9 counties according to 511.org. Conclusion: it is possible to create a coordinated transit system in a spread-out region with multiple metros.
p.s. The German system serves about 5 million residents, with 640 million trips in 2005. The Bay Area has about 7 million residents, with about 500 million trips per year. The Bay Area’s usage of a less well-integrated integrated system is 55% of theirs, measured in trips per person per year year.