Another dangerous factor with these bollards is spacing and design inconsistency. Just because you easily pass through one, doesn't mean you'll clear the next. For example, these two are located about a half mile apart on a local trail:
They look the same. I clear the first with 3" clearance on each side but on the next, there is less than an inch!
From the paint scrapes on the bollards, they get hit on a regular basis.
A few miles down, you encounter these:
A much safer design here since the bollards on both are below handlebar height. The swing gate design is good because it has no edges or corners to catch on. The dark green color is difficult to see in the shade though.
Continuing on, you find this these:
This design has a low lockable swing gate below handlebar height with plenty of space between bollards. The gate backstop in the first pic is only 5' from the bollard though which forces a sharp turn immediately after passing through.
All these designs accomplish the same thing by keeping out vehicles & ATVs yet some are much safer for cyclists. It's interesting to note that all are on the same 10 mile stretch of trail. No consistency at all. I can't help but wonder who designs these things? It certainly isn't anyone with cycling experience.