MY VEHICLE'S BRAKES FAILED RESULTING IN REAR-ENDING THE CAR IN FRONT. THIS HAPPENED ON A FREEWAY GOING STRAIGHT AT 10 AM. MY VEHICLE WAS MOVING AT ABOUT 20 MILES/ HR WHEN I STEPPED FORCEFULLY ON THE BRAKE PEDAL AS THE CAR IN FRONT OF ME SLOWED BUT I DID NOT LURCH FORWARD, MY SEAT BELT DID NOT TIGHTEN TO PULL ME BACK AND MY BAG PACK THAT WAS ON THE FRONT PASSENGER LEATHER SEAT STAYED WHERE IT WAS. MY VEHICLE BEHAVED AS IF I HAD NOT BRAKED. WHEN I STEPPED ON THE BRAKES, I COULD SEE ASPHALT BETWEEN MY VEHICLE AND THE VEHICLE IN FRONT. MY VEHICLE'S FRONT BUMPER, GRILL AND HOOD WAS DAMAGED. THE VEHICLE IMMEDIATELY IN FRONT OF MINE HAD DENTS ON THE REAR BUMPER AND THE TRUNK. THERE WAS A THIRD VEHICLE IN FRONT OF THE ONE IN FRONT OF MINE THAT WAS ALSO DAMAGED, HOWEVER, I DO NOT KNOW THE EXTENT OF THE DAMAGE. THE IMPACT OCCURRED AT A LOW SPEED WHICH DID NOT CAUSE MY SEAT BELT TO TIGHTEN AND DID NOT CAUSE MY BACKPACK ON THE PASSENGER SEAT TO SLIDE FORWARD.