All of the following are sub-groups of Regulatory Traffic Signs except?

Regulatory traffic signs are designed to inform drivers of the laws and regulations that they must follow on the road. These signs can be divided into different sub-groups based on their function. Prohibitive signs indicate what drivers cannot do, such as stop signs or no parking signs. Priority signs inform drivers about who has the right of way, ensuring smooth traffic flow and safety at intersections. Directional signs assist drivers in navigating and provide information about routes, distances, and directions.

However, warning signs serve a different purpose. They are used to alert drivers to potential hazards or changes in the road conditions ahead, such as sharp curves, slippery roads, or pedestrian crossings. While ensuring road safety is crucial, warning signs do not regulate behavior; instead, they inform and warn drivers of changes they may encounter. Therefore, among the choices listed, warning signs do not fit into the sub-groups of regulatory traffic signs.