I watched some road workers struggling with a temporary road-sign on the motorway. When the wind is strong, the sign becomes a sail and are very hazardous. Safety is an enormous issue for road maintenance companies and the potential cost if something went wrong is enormous.
Brilliant idea #77 combines two common technologies.
This perforated material that allows (in this case) wind to pass through it, whilst still be opaque enough to be readible.
And this pop-up design (but more robust).
So rather than the road worker carrying a large, heavy sign across the carriageway and hoping a gust of wind doesn’t cause any problems, they carry one unit (the left hand picture above) and pull-up the sign.