Tennessee Permit Practice Test

What should be your limit when following another vehicle?

1. One car length

2. Two car lengths

3. Three to four seconds behind

4. Five seconds behind

The correct answer is: Three to four seconds behind

The recommended limit for following another vehicle is three to four seconds behind. This time-based rule allows for a safe stopping distance between vehicles. By maintaining this space, a driver gives themselves enough reaction time to respond to sudden stops or emergencies from the vehicle ahead. The three to four seconds measurement is particularly important because it accounts for varying speeds, road conditions, and the performance of different vehicles. Under typical driving conditions, maintaining this distance helps reduce the likelihood of rear-end collisions, providing both the driver and the vehicle in front with a buffer zone for unexpected events. In contrast, following too closely, such as by using a car length or two car lengths as a measure, does not adequately account for differences in speed or the need for braking distance. This approach can lead to dangerous situations, especially in adverse weather or traffic conditions.