FUEL TANK FILLER SPRAYED FUEL ONTO EXHAUST PIPE WHILE UNDER NORMAL INTERSTATE DRIVING CONDITIONS. MY WIFE SMELLED AN ELECTRICAL BURNING SMELL ABOUT 10 MINUTES PRIOR TO THE FIRE WHILE FUELING AT A SERVICE STATION. SHE DISMISSED IT SINCE THERE WAS A NEARBY CONSTRUCTION CREW THAT WAS BURNING TRASH IN BARRELS. SHE THOUGHT PERHAPS IT WAS SOMETHING THEY WERE BURNING. AFTER A VISUAL INSPECTION OF THE VEHICLE, WE CONTINUED ON. *NM