Massachusetts Class D Permit Practice Test 2025 – All-in-One Exam Prep

The safe following distance behind another vehicle in normal conditions is typically considered to be three seconds. This rule allows drivers enough time to react to sudden stops or emergencies from the vehicle in front of them. The three-second rule is based on the concept that a driver should be able to maintain a distance that would allow them to safely stop if needed, helping to prevent rear-end collisions.

To measure this distance, a driver can pick a fixed point along the road (such as a sign or a tree), and begin counting seconds when the vehicle in front of them passes that point. If the driver reaches that same fixed point before counting to three, this indicates that they are too close and should increase their following distance.

In adverse weather conditions or in situations where traffic is particularly heavy, it may be wise to increase this following distance to allow for greater reaction time. The other choices do not represent a safe or practical following distance under normal driving conditions. For example, five feet is far too short to provide any adequate buffer, while a one-second gap may not give enough time to react, and a ten-second gap is generally unnecessary in normal driving situations.