I prefer neighborhood "back" streets, mostly because they're charming. Being empty is nice, too, although if I let my guard down, a squirrel is going to jump under my wheel, or something. But it's quieter, I get to see a lot of different styles of housing, some cool gardens, etc. On the other hand, it isn't every block that you can get under the freeway, and there are only a handful of bridges over the shipping canal, so I wind up on some arterials, too.