What does the 3-6 second rule help a driver determine?

The 3-6 second rule is a guideline that helps drivers maintain a safe following distance from the vehicle in front of them. By counting the seconds it takes for a vehicle to pass a stationary object after the vehicle ahead has passed it, a driver can assess whether they are following too closely. If the count is less than three seconds, it indicates that the driver is tailgating and needs to increase their following distance. This rule is particularly useful because it allows drivers to adjust their speed and spacing based on their driving conditions, promoting overall road safety.