If you are driving a 30-foot vehicle at 55 mph, how many seconds of following distance should you allow?

When driving a 30-foot vehicle at 55 mph, a following distance of 4 seconds is advisable to ensure safe braking and reaction times. The general rule of thumb for following distance is to allow one second for every ten feet of vehicle length. For larger vehicles like a 30-foot rig, you would ideally add additional time to account for the vehicle's weight and the longer stopping distance required.

At 55 mph, a vehicle is traveling approximately 80 feet per second (55 mph ÷ 60 minutes × 5280 feet). A 4-second following distance would equate to about 320 feet (80 feet per second × 4 seconds), which is suitable for a vehicle of this size. This margin allows for sufficient reaction time in case the vehicle ahead suddenly slows down or stops, helping to prevent collisions.

Choosing a shorter following distance, such as 2 or 3 seconds, may not provide enough time to react safely, especially considering the added weight and length of the vehicle, as well as factors like road conditions and visibility. Hence, maintaining a 4-second following distance contributes to safer driving practices, particularly when operating larger commercial vehicles.