When driving behind another vehicle, you should use _________ to keep a safe distance from the vehicle ahead.

Explanation

When driving behind another vehicle under ideal conditions, you should use the two-second rule to keep a safe distance from the vehicle ahead of you. Pick an object in front of you, like a sign post or a tree. When the vehicle in front of you reaches that object, count "one one-thousand, two one-thousand?..". If you reach the object before you count two, you are too close. Slow down until you?ve put enough distance between you and the vehicle ahead of you. In bad weather or heavy traffic, increase your following distance even more.