THE TOYOTA 4 DOOR YARIS SUDDENLY ACCELERATED UPON INITIATING MOVEMENT FROM A RIGHT TURN STOP. THE VEHICLE ACCELERATED TO APPROXIMATELY 30 MPH WITHIN 100 FT. AND CAUSED A HEAD ON WITH FORD 250 TRUCK. UPON IMPACT, THE STEERING WHEEL AIR BAG DEPLOYED AND DRIVER OF THE YARIS SUSTAINED A CONCUSSION, FRACTURED STERNUM AND SEAT BELT BRUISING. THERE WAS SOME DAMAGE TO THE FORD 250 BUMPER AND THE TRUCK NEEDED REPAIRS INCLUDING A NEW BUMPER AND REALIGNMENT OF THE TRUCK VEHICLE TOTAL ALIGNMENT. IT IS UNKNOWN IF THE DRIVER OF THE FORD 250 SUFFERED ANY INJURIES. THE YARIS WAS TOTALED INCLUDING COMPLETE CRUSHING OF THE ENGINE WHICH ENDED UP NEAR THE DRIVER'S SEAT.