Which sign indicates a slow-moving vehicle?

The fluorescent or reflective red or orange triangular sign is specifically designed to alert other drivers that a vehicle is moving at a slower speed than usual. This type of sign is particularly important on roads where higher speeds are common, as it helps to prevent accidents by providing clear visibility and signaling to other motorists that they should exercise caution and be prepared to slow down or pass carefully.

The use of a triangular shape is standardized as a warning sign, and the bright colors make it easy to recognize in various lighting and weather conditions. This ensures that drivers can quickly identify slow-moving vehicles, such as farm equipment or construction vehicles, improving overall safety on the road.

The other options serve different purposes; for instance, the red circular sign usually indicates stop signs or prohibitive actions, the yellow diamond sign is commonly used for cautionary warnings, and the green square sign might denote specific information or directions, which do not relate to slow-moving vehicles.