I WAS DRIVING ON HWY AT 60 MPH FOR APPROX 2 HOURS. WHEN FOOT WAS OFF GAS, CAR WOULD MAINTAIN SPEEDS OF 55-60 MPH. EXITED ONTO EXIT RAMP ON RIGHT. EXIT RAMP WAS APPROX 0.4 MILES LONG, SNOW COVERED, AND UPHILL. APPLIED THE BRAKE ON & OFF WHILE APPROACHING THE STOP SIGN AT THE END OF THE EXIT RAMP, CAR SLOWED TO APPROX 20 MPH WITH BRAKE FULLY PRESSED. RPM'S WERE APPROX 4,000 WITH BRAKE FULLY PRESSED. CAR CONTINUED ACCELERATING WITH BRAKE FULLY PRESSED. COULDN'T STOP, BUT WAS ABLE TO TURN LEFT AND CROSS BRIDGE OVER HIGHWAY. TRIED PUTTING FOOT UNDER GAS PEDAL TO SEE IF IT WAS STUCK DOWN, BUT IT WAS NOT DOWN. CONTINUOUSLY TRIED TO BRAKE, BUT COULD NOT SLOW THE CAR TO BELOW 20 MPH EVEN WITH BRAKE FULLY PRESSED. ROADS WERE SNOW COVERED. WENT APPROXIMATELY 0.5 MILES ON PRAIRIEVIEW RD. NO CARS WERE STOPPED AT RED LIGHT ON PRAIRIEVIEW AS I APPROACHED. FULLY PRESSED AND HELD DOWN BRAKE RIGHT BEFORE COMING TO RED STOPLIGHT ON PRAIRIEVIEW RD & OAK ST/US-150. CAR WOULD STILL NOT GO BELOW 15-20MPH. TURNED RIGHT TO AVOID CROSSING INTO ONCOMING TRAFFIC. LOST CONTROL OF THE CAR AND BEGAN SPINNING ON THE SNOW. BRAKE WAS STILL FULLY PRESSED DOWN BUT ACCELERATING AT 3,000 RPM. CAR DID TWO 360'S ON OAK ST/US-150 CROSSING INTO ONCOMING TRAFFIC AND WENT INTO DITCH ON LEFT SIDE OF THE ROAD. CAR WAS STILL ACCELERATING, CAME OUT OF THE DITCH AND BACK INTO ANOTHER 360 ON OAK ST/US-150. THEN CAR WENT INTO THE DITCH ON THE RIGHT SIDE OF THE ROAD. FRONT RIGHT PASSENGER DOOR HIT WOODEN SI