A "Do Not Enter" sign is a traffic control device used to indicate that vehicles are not allowed to enter a specific area or roadway. This sign is typically rectangular with a red circle and a white horizontal bar, clearly signaling that entry is prohibited. It helps maintain safety by preventing drivers from entering one-way streets or restricted zones. These signs are commonly found in urban areas, near construction sites, or in parking lots. They play a crucial role in traffic management, ensuring that drivers follow the rules and reducing the risk of accidents. Proper placement of a Do Not Enter sign is essential for effective communication to road users.