What must a driver do when a traffic light turns red?

When a traffic light turns red, the correct action for a driver is to stop and wait for the light to change. This rule is fundamental to traffic laws and is designed to maintain safety on the roads. Stopping at a red light allows for the orderly flow of traffic and protects pedestrians who may be crossing the intersection. Waiting for the light to turn green ensures that all vehicles adhere to the traffic signals and that individuals in the intersection have cleared the way for safe passage.

The other options are important to consider in the context of traffic safety. Slowing down and observing may not comply with the law, as the requirement is to stop completely at a red light. Continuing to drive or accelerating to pass through an intersection when the light is red can lead to serious accidents, as it disregards the signal indications other road users are relying on for safe navigation. Therefore, stopping and waiting for the light to change is necessary for promoting safety and adhering to traffic regulations.