We've done some ski resorts around here over the years... nothing on a large scale, but all of the
signs were 3/4" MDO or sandblasted 6/4" redwood and pvc for the interior
signs for all sorts of needs.
We always tended to use a material that is rather thick so if someone did happen to slip or run into the side of a
sign... at least their head won't be sheared in half. They'll have a nasty bruise, but that's expected at a place with this sort of activity going on. That's what the bar is for..............
Also, I don't know what HVC posts are.