What is the proven and recommended method for keeping proper distance from the vehicle driving in front of us?

1. Drive as similarly as possible to the drivers in the adjacent right and left lanes,.
2. Correct answer: The “two-second count” method.
3. Vehicle length and engine volume method.
4. Estimating a reasonable distance between yourself and the vehicle driving in front.

WhyThe proven way to keep your distance is the two-second rule. When the car ahead passes a landmark, count 'one thousand one, one thousand two': if you reach it sooner, you are too close. Judging by eye is deceptive, and other lanes are no reference.