What is the safest distance to follow behind a large truck on the expressway?

Following at a distance of 3-4 seconds behind a large truck on the expressway is recommended because it provides adequate space for reaction time and safety. Large trucks have significant blind spots, and maintaining this distance allows a driver to see beyond the truck and be aware of any obstacles or traffic that may arise. This distance also helps in assessing the road conditions ahead and reacting to sudden stops or slowdowns from the truck.

In inclement weather or challenging road conditions, increasing this following distance further can enhance safety, as larger vehicles can require longer stopping distances. While shorter distances, like 1-2 seconds, may seem manageable under ideal conditions, they do not account for the need for additional time to react when following larger vehicles, which have different dynamics than smaller cars. Therefore, the 3-4 seconds range is a well-established guideline aimed at ensuring the safety of both the driver and the larger vehicle on the road.