If the car in front of you stopped suddenly for any reason, it is quite possible that you collide with the rear of that car as you might not be able to stop your car in the suitable time.
Due to this, and for safety issues, To avoid tailgating, and help avoid a rear-end collision, you should give yourself a gap of 3 seconds behind the car in front of you just to make sure that you will have enough time and space to stop your vehicle in the suitable time before colliding.
