Interesting - and in our area - controversial subject. And I am borrowing this subject somewhat to our area....and in general.
Tucson is proud to be a "Bicycle Friendly City" or something like that. And I used to cycle and run a lot.
I believe AZ law says for 3 (maybe 4) foot clearance by a motor vehicle. On a two lane road - with no bike lane or one not used properly - this means you will have to be over the center line with your vehicle even if they are single file.
But here we have issues as large groups cycle and come out here to the narrow roads outside of town - like even 25 or more of them. And, quite often, they ride 2 and 3 abreast blocking the lane on a two lane road. I guess so they can chat.
Some places have 3 or 4 foot bike lanes which cyclists want to ride the white line that separates that lane from the road instead of being in the center of it (less gravel, dirt, etc is the reason).
So traffic backs up. And, do I need to say it, tempers flare.
I will at all times give a law abiding cyclist - or a stupid runner who is running with traffic instead of against it - at least 3 to 4 feet, even waiting to use the other lane if I have to.
However, if they flagrantly abuse the law, I carefully narrow my margin and slowly pass (rare occasion). This gives them all the opportunity to kinda wave and say hello to me (so to speak).
But, I will never do anything unsafe.