I WAS DRIVING MY CAR ON THE FREEWAY IN STOP AND GO TRAFFIC. I HAD A GOOD 3-4 CAR LENGTHS IN BETWEEN MYSELF AND THE VEHICLE IN FRONT OF ME. THE CARS IN FRONT OF MY CAME TO A SUDDEN STOP SO I SLAMMED ON MY BRAKES. THE CAR INITIALLY SLOWED BUT NOT AT THE PACE I EXPECTED. I PUSHED THE BRAKES TO THE FLOOR BUT THE CAR WOULD NOT STOP. I REAR ENDED THE VEHICLE IN FRONT OF ME TOTALING THE CAR. THERE WAS PLENTY OF ROOM IN FRONT OF ME AND THE ROADS WERE DRY. THE CAR SHOULD HAVE STOPPED IN TIME WHICH LEADS ME TO BELIEVE THE BRAKES WERE THE CAUSE. I HAD NOTICED THEM BEING DELAYED IN THE WEEKS PRIOR BUT DID NOT HEAR ANY SQUEAKING SO I ASSUMED THEY WERE FINE UNTIL THIS HAPPENED.