Interesting. In the area where I live there are a ton of MUPs that run alongside roads (i.e. one side of the street will have a MUP instead of a sidewalk), but my experience has been that they are far more dangerous to ride at anything above weaving-recreational-cyclist pace because at the intersections cars around here are simply not used to looking at the MUP for bicycle traffic. I cannot tell you how many times I was nearly right-hooked or left-hooked crossing through intersections on the MUP around here when I first started cycling.

Once I started using the road I found that I'm far safer at intersections because the cars tend to actually *see me*, and the roads around my area aren't busy enough to bring in the dangers that cyclists typically face on city streets.