No, I saw nothing official. I apply the same rules for running on a MUP as I do for running on roads. I take into account the fact that I don't actually trust other cyclists in this region for being a bit more gun-shy about turning my backside on a 200 lbs. + missile cruising a MUP at upwards of 20 MPH. My speed range is not empirical, or documented by devices clocking them specifically, but I can say that I've had sprints alongside the MUP with some of these cats where I was pushing a 20 MPH line on a side street and they passed me by a few dozen yards easily at the visible markers I'm using. They weren't racing me and I've seen a few of them consistently. Teeth gnashed, big ringging on the MUP.

I honestly wouldn't run "with the flow" of these peeps or the other slower traffic on the MUP I see that consists of bobbling people with helmets over their eyes on mountain bikes with their knees buckled out. There are obviously exceptions to this, where I see very considerate riders that even slow down to make eye contact with me before passing (hence reinforcing my theory that I'm better, safer and more visible running in the opposite direction of traffic. They see my headlight, and I see theirs (when they're not ninjas). Otherwise, the first thing I usually hear in the dark is "hey!" because I've killed their elite night vision with my beam of headlight.