Under normal driving conditions, the following distance at 55 mph on the expressway should be a minimum of how many seconds?

Under normal driving conditions, the following distance at 55 mph on the expressway should be a minimum of how many seconds?

• A. 1 second.
• B. 2 seconds.
• C. 4 seconds.
• D. 3 seconds.

Answer: (D)

A safe following distance is measured by time, not a fixed feet distance. At highway speeds, you want about a three-second gap under normal conditions. That three-second buffer gives you enough time to notice the car ahead slowing or stopping and to react and brake without impact. At 55 mph, you’re covering roughly 80 feet every second, so a three-second gap puts about 240 feet of space between you and the car in front. One or two seconds is too short for high speeds, increasing the risk of a rear-end collision, while four seconds would be safer but isn’t the minimum under normal conditions. If conditions are worse—rain, fog, or poor visibility—extend the gap to four seconds or more.

A safe following distance is measured by time, not a fixed feet distance. At highway speeds, you want about a three-second gap under normal conditions. That three-second buffer gives you enough time to notice the car ahead slowing or stopping and to react and brake without impact. At 55 mph, you’re covering roughly 80 feet every second, so a three-second gap puts about 240 feet of space between you and the car in front. One or two seconds is too short for high speeds, increasing the risk of a rear-end collision, while four seconds would be safer but isn’t the minimum under normal conditions. If conditions are worse—rain, fog, or poor visibility—extend the gap to four seconds or more.