Commercial Driver’s License (CDL) Test 2025 – 400 Free Practice Questions to Pass the Exam

The correct following distance for a large truck is at least 4 seconds behind the vehicle in front. This recommendation is based on the understanding that large trucks require more time and distance to stop safely compared to smaller vehicles due to their size and weight.

A 4-second following distance provides adequate space to react to sudden stops or emergencies ahead. It allows drivers enough time to perceive what is happening in front of them, assess the situation, and apply the brakes appropriately. This distance also accounts for factors such as road conditions, weather, and the truck’s load, which can all impact braking distance.

Additionally, when maintaining this following distance, it is essential to adjust for factors like high speeds or adverse weather conditions, where even more space may be necessary to ensure safety. Adopting a 4-second rule helps enhance safety for both truck drivers and other road users.