which bridge: a wee geographic project

While trying out the automated route function of an automated road atlas to see what it recommends on some trips I'm planning, it occurred to me that while automated route-planning is inept in many ways, it could tell me with little fuss which of the various bridges across San Francisco Bay is the shortest route between two places on opposite sides. So I tested it out on various pairs of inner Bay communities and got this little table here, with the selected Marin & Peninsula cities in rows and the East Bay cities in columns:

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Of course this isn't always the best route, due to traffic, or a preference in taking the free direction on the Richmond bridge over the high-toll direction on the Golden Gate, or whatever. But these are the shortest routes as measured from whatever DeLorme considers the center of town. Milpitas and San Jose are also included in the East Bay listing as the only Peninsula towns for which the Golden Gate Bridge isn't always the shortest route to Marin.

I'd long suspected that the San Mateo bridge is good only for a relatively small set of destinations on each end, and now I confirm that's so. I also find that, living at the far west end of San Jose, I'm actually in a place where the Dumbarton Bridge would be a shorter path to the East Bay than 880, which I normally take.