Steering wheel vibrates when brake is applied when running at freeway

Sounds like the front brake rotors are warped. Common thought says to machine them flat again if thick enough. Problem with this is that the reason they are warped is because they are not disipating heat and have warped. If machine and make thinner then will have a harder time disipating heat. I recommend replacing them, pads too if old enough or thin enough, if they were overheated or cracked. Look for a caliper hanging up either by mounting/slide problems or hydraulic problems. This will cause prob all over again. There is not much thickness on rotors as it is. Classic symtoms.