WHILE TRAVELING AT LESS THAN 20 MPH, THE DRIVER IN FRONT SLAMMED INTO THE CAR IN FRONT OF THEM (NO BRAKE LIGHTS). I IMMEDIATELY STOMPED ON THE BRAKES... THE HIGHLANDER SLOWED VERY BRIEFLY AND THEN WENT "NUMB". THE HIGHLANDER CAME TO A STOP ONLY BY HITTING THE CAR IN FRONT OF ME. THERE WAS PLENTY OF ROOM TO STOP AND IT SHOULD HAVE. THIS IS THE 3RD TIME THE HIGHLANDER HAS "LOCKED UP" ON SUDDEN SHORT STOPS.*AK