If you've read my other reviews, you know that I can tend to get lost a lot when I drive (even when I have GPS). In San Fran, I kept accidentally getting on I-80-- and there way nowhere to turn around until Oakland. Bleh! The entrance is poorly market when you are exploring around on the Oakland side of Market Street and then you're suddenly on the highway with no way to get off. One thing I do have to give high marks, though is public transportation. You can get a bus easily from San Fran to Oakland to catch a plane. I didn't really need to rent the car after all.