Sorry I'm coming to the thread late, but I'm a Davis student now and I drive from the east bay every day. Two points to consider:
The traffic Nyanko's neighbor is driving in, from Davis to east bay/SF in the morning and east bay/SF to Davis in the evening, is *horriffic*. But there's actually not much traffic in the opposite directions. It takes an hour each way, but it's a really consistent and predictable hour.
However... you don't want to commute from SF to Davis, Karazy. Traffic within SF is bad, and you'll either have to cross two bridges or fight your way along a crowded little highway around the top of San Pablo Bay. Just pop up a map on Google and look at the difference between SF to Davis and the east bay (e.g. Oakland) to Davis and you'll see what I mean. (Actually, do it during the morning or evening commute hours and flip on the "traffic" setting!)
I assume your reason for asking is that SF is a way cooler place to live than Davis, and not that you have strong personal reasons (e.g. spouse with job) to need to do it. My advice is to live in Davis and visit SF on the weekends if you just want the atmosphere. If you do have a spouse situation, then I'd suggest a compromise of living in the east bay instead of SF (and if you'd like specific advice in that case, feel free to PM me).
