Colliding with a car that is clearly mostly in front of you will often result in your being ticketed for not being in control of your vehicle. To a point, you are responsible for avoiding an accident if possible, and not doing so puts you at fault.
And I'm talking about generalizations here. You can always take a specific incident and say what someone should or shouldn't do, but generally speaking, avoiding a collision with another car is the best course of action. So many unexpected things can happen when you make contact with another car.