AFTER SWITCHING TO PASSING LANE AND SEEING TRAFFIC IN LANE AT STANDSTILL I SWIFTLY JAMMED ON BRAKE PEDAL. BRAKES FAILED TO PROVIDE ADEQUATE STOPPING ABILITY AS THOUGH THEY WERE COATED WITH GREASE. DESPITE HAVING WELL IN EXCESS OF 100 FT THE VEHICLE WOULD NOT STOP. REAR ENDED VEHICLE IN FRONT WITH ABOUT 12K IN DAMAGE TO FRONT OF THE VEHICLE. AIR BAGS DID NOT DEPLOY. ORIGINAL ROTORS AND PADS WERE REPLACED AFTER EXPERIENCING SEVERE BRAKE FADING WHEN HOT PRIOR TO ACCIDENT. DRILLED AND SLOTTED RACING ROTORS WERE INSTALLED. AFTER THE VEHICLE WAS REPAIRED AND PLACED BACK ON THE ROAD, I TESTED WITH THE SAME BRAKES WITH A HARD STOP FROM 80 MPH. THE BRAKES WORKED SO WELL THE FORCE OF THE STOP WAS PULLING ME OFF MY SEAT. SEVERAL WEEKS LATER, I WAS CUT OFF BY ANOTHER DRIVER ON THE HIGHWAY DOING ABOUT 40MPH LESS THAN I WAS. I JAMMED ON THE BRAKES AND AGAIN THERE WAS INSUFFICIENT BRAKING LIKE BEFORE EXCEPT NO COLLISION. ONCE MORE I TESTED AT A HARD BRAKE FROM 80 MPH AND AGAIN IT STOPPED EXTREMELY WELL. APPARENTLY THE FAILURE OF SUFFICIENT BRAKING CAME WITH APPLICATION OF ABS SYSTEM OTHERWISE THE STOPPING POWER WAS EXCEPTIONAL. I STRONGLY URGE INVESTIGATION OF GM ABS BRAKING. I AM A PROFESSIONAL DRIVER WITH IN EXCESS OF 4 MILLION MILES WITH ALL CLASSES OF VEHICLES IN ALL EXTREMES. THE WORST DAMAGE I EVER HAD ON THE HIGHWAY WAS A BROKEN HEADLIGHT IN 1975 UNTIL THIS ACCIDENT. THE ACCIDENT SHOULD NOT HAVE HAPPENED AS MY REACTION WAS TIMELY AND THE DISTANCE TO STOP MORE THAN ADEQUATE. THE AIR B