What does a red traffic light indicate?

A red traffic light indicates that a driver must stop completely before the intersection or at the designated stop line. This is a fundamental traffic rule designed to control vehicle flow and ensure safety at intersections. When a red light appears, it signals that it is not safe for vehicles to continue moving, thereby preventing potential collisions with cross traffic or pedestrians who may be in the intersection.

Understanding this rule is crucial for all drivers since it helps maintain order on the road and protects everyone involved. The complete stop allows drivers to assess the situation before proceeding once the light turns green, ensuring that they are not putting themselves or others at risk.

The other options do not accurately describe the action required by a red light. Preparing to stop, for example, is an action associated with yellow lights, while warnings for pedestrian crossings are indicated by different signs or signals, not by a red light. Proceeding with caution is more relevant to situations indicated by yellow lights or controlled intersections where traffic can change.