What parts of San Francisco, Oakland, and Berkley are off limits to traffic?

Question

Somebody on the newsgroups and on here said that parts of all three cities are car-free zones.

Answer 1

Um... not really.  All three cities have tiny sections of a block or two where the street has been turned into plaza.  For instance the east end of Fulton Street is UN Plaza.

All three cities use tricks to discourage cars on certain routes but they do not restrict bicycles nearly as much.  For instance Berkeley put diagonal barriers all over their residential street grid, so you can't cut through neighborhoods anymore with a car - but you can with a bike.  

San Francisco has transit preferential streets, that are set up to be lame for cars but ideal for buses and streetcars (Hayes).  Or some streets have transit-only lanes Geary, Judah, 3rd). Some roads gave up a traffic lane to have a bigger bike lane.  There's a fairly nice (but far from ideal) bike route network.