Safety on rough roads:

I've pinch flatted, where the tire bottoms out against the edge of the rim, mashing the inner tube and putting a small slit or a pair of slits in the tube. A "snakebite".

Faster speeds make pinch flats more likely.

Pinch flatting is related to the sharpness of the edges of the pothole, sewer grate, or rock chunk on the road, and also the energy from a fast hit. My flats were on downhills at speed, on otherwise smooth roads, hitting inch wide sharp piecesof rock that were kicked out on the road. Years ago, I flatted on the edge of a manhole cover frame, with a pothole in front of it.

At slow to moderate speeds, none of these would have caused a flat. At very fast downhill speeds, even a rounded pothole might cause a pinch flat.