Which signal is commonly used to indicate a danger zone?

Warning signs or flags serve as a widely recognized means of indicating a danger zone in various settings, including construction and utility work. These visual signals are designed to alert workers and the public to hazards nearby, thereby enhancing overall safety. They often feature bold colors and clear symbols or messages that convey the nature of the danger, making them easily noticeable from a distance.

While traffic cones can also mark areas of concern and colored tape might be used for demarcation, they don't necessarily communicate the same level of immediate warning that signs or flags do. Voice commands can provide important information but rely on auditory communication rather than visual cues, which can be less effective in many noisy or busy environments. The use of warning signs or flags combines visibility with clear communication of risks, making them the preferred method for indicating danger zones.