What does a left turn only sign indicate?

A left turn only sign indicates that vehicles must turn left at the intersection and are not permitted to go straight or turn right. This sign plays a crucial role in regulating traffic flow and preventing accidents by clearly instructing drivers on how to navigate the intersection safely. It helps to streamline movements and minimize confusion, ensuring that drivers understand the required action at that specific point.

While the other options suggest varying interpretations or conditions that do not apply to the sign's intention, the clarity of the left turn only sign is definitive and does not depend on context or location-specific variations. Thus, the statement regarding the indication of a left turn only sign being true is accurate.