What is the proper following distance when driving a commercial vehicle?

Answer: C — minimum of 4 seconds

The proper following distance when driving a commercial vehicle is a minimum of 4 seconds. This guideline is especially important for commercial drivers as these vehicles are typically larger and heavier than standard vehicles, which results in a longer stopping distance. A following distance of 4 seconds allows for adequate space to react to sudden stops or emergencies, ensuring the safety of the driver and other road users. This distance also accounts for various factors that can affect stopping distances, such as road conditions, weather, and the load being carried. By maintaining a 4-second gap, drivers have more time to assess the situation ahead, adjust their speed as necessary, and apply brakes safely when required. This practice is part of defensive driving strategies that help prevent accidents and collisions.