About 15 years ago a group of us on our usual at that time Saturday morning ride encountered the usual placement of the bollards and we all went around them except one who was not paying attention and ran straight into one, the middle one of the three. Fortunately it was not a carbon frame as it no doubt would have failed. The frame was steel and it simply bent the fork, but not the top or down tubes.
I no longer ride any MUP unless there is no alternative which is unlikely. Between dogs, walkers/runners, and people riding way to fast on the MUP, I find that environment unsafe, and find it easier to deal with motor vehicles.