DRIVER PERFORMED A PRE-USE WALK AROUND INSPECTION ON VEHICLE AND OBSERVED NO DAMAGE. DRIVER PROCEEDED ON TO DESTINATION. DRIVER MERGED ON TO HWY 70 EAST AND ACCELERATED TO THE POSTED SPEED LIMIT OF 75MPH AND SET THE CRUISE CONTROL. WITH NO OTHER VEHICLES AROUND THE DRIVER, ON OR AROUND MILE MARKER 184, THE VEHICLE STARTED TO MAKE A LOUD GRINDING SOUND AND VIOLENTLY VIBRATED. THE DRIVER PRESSED THE BREAK TO DISENGAGE THE CRUISE CONTROL AND LOOKED AT THE CENTER FLOORBOARD TO INVESTIGATE THE PROBLEM WHEN ALL AT ONCE THE FLOORBOARD EXPLODED SENDING SHRAPNEL AND DEBRIS UPWARD. FLAMES WERE COMING UP FROM THE FLOORBOARD IMMEDIATELY FILLED THE CAB WITH SMOKE. AT THE SAME TIME AS THE EXPLOSION OCCURRED, BOTH THE DRIVER SIDE AND PASSENGER AIRBAGS DEPLOYED. WITH THE AIRBAGS DEPLOYED AND SMOKE FILLING THE CAB, THE DRIVER HAD ZERO VISIBILITY WHILE THE VEHICLE WAS STILL IN MOTION. USING THE REMAINING VEHICLE MOMENTUM, THEY STEERED TO THE RIGHT TO GET THE VEHICLE OFF THE ROAD AND WAS ABLE TO GET THE VEHICLE 90% OFF THE ROAD. THEY WERE UNABLE TO PUT THE VEHICLE IN PARK OR REMOVE THE KEYS FROM THE IGNITION. THEY TURNED ON THE HAZARD LIGHTS AND EVACUATED THE VEHICLE TO A SAFE DISTANCE. FROM AFAR, THE DRIVER OBSERVED FLAMES DRIPPING FROM THE BOTTOM OF THE VEHICLE AND WITH NO EXTINGUISHER THEY CONTACTED THE POLICE AT 678-1234 AND INFORMED THEM OF MY NAME AND THE INCIDENT?IN TURN THEY INSTRUCTED THE DRIVER TO DIAL 911. AFTER APPROXIMATELY 10 MINUTES, THE WHITE SANDS MISSILE RANGE FIRE