What does it mean when a circle with a line through it appears on a sign?

A circle with a line through it commonly indicates that a specific action is prohibited. This is a standard symbol in traffic signage, designed to easily communicate to drivers that certain behaviors, such as making a U-turn or parking in a restricted area, are not allowed.

The form of this sign effectively conveys a clear message: the action is entirely off-limits. This prohibition is meant to enhance safety and ensure smooth traffic flow. For instance, a "No U-Turn" sign is typically used at intersections where such maneuvers could lead to accidents or navigate to conflicting traffic patterns.

Understanding this symbol is essential for all drivers as it helps ensure compliance with traffic laws, thus promoting safety for everyone on the road.