MY MOTHER AND I WERE DRIVING SOUTH ON I-95, MILE MARKER 277 (NORTH OF DAYTONA) WITH THE CRUISE CONTROL SET FOR 72 MILES PER HOUR. I WAS IN THE RIGHT LANE, AND AS I APPROACHED A CAR GOING SLOWER, I APPLIED THE BRAKES TO RELEASE THE CRUISE CONTROL. IT WOULD NOT TURN OFF, SO I MOVED TO THE LEFT LANE AND TRIED REPEATEDLY TO RELEASE IT. I WAS ABOUT THE HIT THE REAR OF THE CAR INFRONT OF ME, AND IT SEEMED LIKE I WAS ACCELERATING RATHER THAN DECELERATING. I COULD NOT SLOW DOWN SO WENT INTO THE MEDIAN STRIP, AND STILL WAS UNABLE TO SLOW DOWN.IT SEEMED I WAS UNABLE TO EVEN DEPRESS THE BRAKE PEDAL. IT SEEMED FROZEN. IT WAS ROUGH GOING, AND I WAS AFRAID OF GOING INTO THE NORTHBOUND LANES, SO I STEERED THE CAR TO THE RIGHT, AND SEEMED TO SLIDE ACROSS THE NEAREST LANE INTO THE SIDE OF A U-HAUL TRUCK. THE IMPACT SPUN US AROUND AND WE CAME TO REST IN THE MEDIAN STRIP.