My wife and I are occasional (1/month) MUP users on the tandem. The paved path is narrow and goatheads await those who stray. We'll do 19-20 (we're slow) with nobody in sight, slow down in the vicinity of other cyclists, really slow way, way down in the vicinity of kids (we have young grandkids). Most cyclists are prudent on MUPs, but there are exceptions and they give all of us a bad name.