What is the "three-second rule"?

The three-second rule serves as a crucial guideline for drivers to maintain a safe following distance under normal driving conditions. By measuring the time it takes for a vehicle to reach a certain point after the car in front of you passes it, you ensure that you have adequate space to react in case of sudden stops, reducing the risk of a collision. This distance allows for a buffer, accounting for different speeds and potential hazards on the road.

This rule is particularly important because it promotes safe driving practices and helps prevent rear-end accidents, a common type of collision. Tailgating significantly increases the likelihood of accidents since it limits the driver's ability to respond to traffic changes. It’s recommended to increase this following distance in adverse weather conditions or when driving in heavy traffic to ensure additional safety.

The other options address different aspects of driving but do not pertain to the primary purpose of maintaining a safe distance between vehicles on the road. For example, signaling before changing lanes involves communication with other drivers, while waiting at a stop sign is more about traffic management and obeying signals. The merging into traffic involves timing and adjusting speed rather than establishing a safe following distance.