I came over it westbound about 1630 yesterday with an empty flat bed trailer and I was fighting the wind coming over the top. The problem with signs are that drivers carry on thinking " I’m not high so I’m ok".
Instead of saying closed to high sided vehicles it should say closed to all vehicles over a certain height. As has been mentioned, put a copper or even a womble at Scotch or Penrith end to stop highsiders joining the road.
If, god forbid the worst happened, who would take responsibility for it while the authorities “plan” to stop highsiders using the road?