What sign is not a recommended means of communicating with others users of the roadway?

Using hand signals is generally not recommended for communicating with other roadway users, especially in high-traffic situations. While they can be useful for cyclists or motorcyclists, they may not be clearly visible to drivers in cars or trucks. Additionally, hand signals can be misinterpreted, leading to potential accidents. Instead, using vehicle signals and brake lights is safer and more effective for conveying intentions on the road.