Just a thought about riders in "packs". At least when they're in packs, you can pass bunches at a time. I'd rather have to pull all the way over to the other lane and pass a bunch, then have it clear, like when passing a car, than to have them strung out for a mile where you're placed in a position of "lane sharing".
From my own experience as a "runner" I go to great effort to stay away from cars on the road. I run against traffic, so I can see cars coming, and, when I do, I head for the shoulder whenever possible. I never like to be in a position where the cars are approaching me from behind because I never know if the driver is paying attention. Also, it's very hard to hear them coming, especially when it's windy.
From my experience, I've also been in a position (common also to cyclists) where there just isn't a shoulder for a portion of the route I'm on. In that case, trying to get too close to what there is of a shoulder is dangerous. This is where cyclist and runners haven't much choice but to "take the lane" so keep from being squished into the guardrail or going off into a ditch.
I'm constantly aware that only a split second means the difference between life and death for me.
Also, based on my own road-sharing needs and experiences, I always allow as much space when overtaking pedestrians and bikers as possible. All I can think about is how bad I'd feel if I hit someone, maiming or killing them, regardless of who's "fault" it was.
In closing, my only plea to fellow motorists, tractor owners and pedestrians on the board is to please try to have some patience and mercy on those with whom you share the road.