And then when the car in front has to tap the brakes for whatever reason, the tailgater has to slam them to avoid a collision, the person tailgating them also s

And then when the car in front has to tap the brakes for whatever reason, the tailgater has to slam them to avoid a collision, the person tailgating them also slams theirs, and you get a wave of braking propagating backwards, eventually creating a traffic jam.