I HAD A 2018 TESLA S. I WAS DRIVING NORTH ON US 395 IN LANE 2 OF A 4 LANE DIVIDED HIGHWAY AT 0030 ABOUT 20 MILES SOUTH OF LONE PINE, CA. IT WAS PITCH BLACK OUT. I WAS THE DRIVER OF A TESLA S IN SEMIAUTONOMOUS DRIVER-ASSIST MODE. THE ROAD WAS GOING UP HILL AND I CLICKED MY TURN SIGNAL TO PASS A SEMI TRAILER AND MY CAR WENT INTO THE LEFT LANE AND PASSED THE TRUCK. AFTER GOING A SIGNIFICANT DISTANCE IN FRONT OF THE TRUCK AND STARTING DOWN HILL AND I CLICKED MY TURN SIGNAL TO RETURN TO THE RIGHT LANE. THE CAR WENT INTO THE RIGHT LANE AND CONTINUED ONTO THE RIGHT LANE BUT CONTINUED ABRUPTLY ONTO THE SHOULDER. IT FELT LIKE THE STEERING WHEEL TURN TO THE RIGHT AND WE WENT OFF THE ROAD INTO A DITCH 15-20 FEET BELOW. MY HANDS WERE ON THE STEERING WEAL, A FACT I CAN PROVE BECAUSE I SUFFERED A FRACTURE OF THE THIRD METACARPAL HEAD OF MY LEFT HAND, A FRACTURE AN ORTHOPEDIST CALLED AN "AIRBAG FRACTURE". ALSO THERE WAS BUSING OF MY DISTAL DIGITS OF THE FINGERS OF MY LEFT HAND. THE CAR WAS A TOTAL LOSS. MY WIFE WHO WAS SLEEPING AT THE TIME WAS IN THE FRONT PASSENGER SEAT AND SUFFERED SIGNIFICANT TRAUMA FROM HER SEAT BELT, A FRACTURE OF THE LATERAL SPINE OF C-7, BILATERAL FIRST RIB FRACTURES, STERNUM FRACTURE AND A T-12 BLOWOUT FRACTURE. I HAVE COPIES OF MY X-RAY OF MY HAND FRACTURE AND A PICTURE OF THE ECHYMOSIS OF MY FINGERS. I REPORTED THE ACCIDENT TO TESLA WITH THE DATE AND TIME OF THE ACCIDENT AND WAS TOLD THEY WOULD GET BACK TO ME AFTER INVESTIGATING, BUT THEY HAVEN'T.