Usually the thin small ones are removed in the season, and the asphalt ones have signs. This is the same reason the speed bands/rumble strips are concave not b

Usually the thin small ones are removed in the season, and the asphalt ones have signs. This is the same reason the speed bands/rumble strips are concave not bumps. City plows also have shock absorbers systems that let them ride the bump, but you do get ice pockets after the obstacle.