When should the four-second rule be applied?

The four-second rule should be applied in bad weather conditions, such as when the road is wet or slippery. This rule is crucial for maintaining a safe following distance between vehicles, allowing for sufficient time to react in case of emergencies. When the road is wet, the risk of skidding or losing control increases, so having an extended following distance helps mitigate these risks. The four-second rule gives drivers more time to stop safely, which is particularly important in adverse conditions where traction may be compromised. By adhering to this guideline during inclement weather, drivers can enhance their safety and that of others on the road.