If it's a solid line with no bike lane, then it's the same as if you were passing a car, i.e., illegal. I've been ticketed for that in SF.
Cyclists significantly slowing traffic on major arterials IS a problem and sanctimonious truisms are not the solution. The solution is bike lanes or entire separate "bike arterials" which run parallel to "car arterials" so the two wildly different transportation mechanisms don't get in each others way too much.
Cyclists are not a problem. They are a group of road-users. Equally entitled to use the roads as every other legal road-user.
After n years. Time to sign out from HN.
Edit: actually, I would probably hit the squirrel. Swerving/sudden speed changes are often far more dangerous. Hopefully the point holds: if you always feel the need to fail safe, then expect congestion and traffic problems.
Legally, a bicycle has the same legal right to the road and lane as you and your car does. You must not encroach on that.
Legally, in California, a bicycle that isn't maintaining the "normal speed of traffic" for the road it is on is required to be operated as close as practical to the right-hand curb except in specifically enumerated circumstances. It does not have the same legal right to the road and lane as a car does. (California Vehicle Code Sec. 21202)
IIRC, in California, it isn't illegal to share a lane, (though it still may be a bad idea) but its illegal to straddle lanes.
Legally, you can; the width of cars and bikes are actual facts, of course, but I don't think you'll find a fixed-in-law minimum distance for most of those things in the California Vehicle Code.
EDIT: I meant a two lane road. I'm in the left lane. Cars are parked in the right lane sporadically. A cyclist is in the right lane, but veers into the left lane to go around it.
I don't know whether to feel reassured or what, but I'd rather sky dive to work than ride in the road while the average person drove by me.