One very good way to ensure that you are following far enough behind other cars is to Watch as the vehicle ahead of you goes past a road sign or fence post. It should take at least three seconds for you to reach the same spot on the road.
When driving, it is important that you stay far enough away in front of you such that if they were to come to a sudden stop, you would have ample time to react and come to a stop as well.
One way to do this is to observe the car ahead of you going past a landmark such as a road sign or a fence post. If you find that you take less than three seconds to pass the same landmark, then you are too close to that car.
The first option is incorrect because the cars next to you might be maintaining an incorrect distance and using them as a measure would make you incorrect as well.
The second option is incorrect as well because estimating distances is not a good enough way to ensure that you are a safe distance away.
It is best to observe the car ahead of you and ensure you pass a landmark more than three seconds after they do.
Benefits of the "three seconds rule" are shown here https://brainly.com/question/9287489.
