What does a warning sign usually indicate?

A warning sign is typically used to alert drivers to special conditions or hazards that might not be immediately obvious, enabling them to navigate the roadway safely. These signs serve as a proactive measure to inform drivers of potential dangers ahead, such as curves in the road, slippery surfaces, or pedestrian crossings. By providing advance notice of these situations, warning signs encourage drivers to reduce speed, be more cautious, and prepare for whatever challenges may lie ahead, thereby enhancing road safety.

The other options represent different types of signs: speed limit signs communicate specific speed regulations that must be adhered to, regulatory signs enforce laws that drivers must follow, and exit instruction signs guide drivers on highway exits. Each of these serves unique purposes, distinct from that of warning signs, which focus on alerting drivers to hazards rather than regulating behavior or providing directional guidance.