IGNITION SHUT OFF ON MASSACHUSETTS TURNPIKE WHEN TRYING TO CHANGE FROM NORMAL (ELECTRIC) TO HOLD (GAS) MODE. MODE BUTTON IS TOO CLOSE TO IGNITION POWER BUTTON. I HAD TO STOP IN RUSH HOUR TRAFFIC TO PUT CAR IN DRIVE AND RESTART, COULD HAVE BEEN HIT. I CALLED ONSTAR EMERGENCY SERVICE IN THE MOMENT, BUT THEY WERE NOT AWARE OF A WAY TO RESTART THE CAR WHILE IT WAS ROLLING. DISCOVERED LATER THAT THERE IS A 3-STEP PROCESS TO RESTART THE CAR WHILE IT'S STILL MOVING, BUT IT IS COMPLICATED AND DIFFICULT TO REMEMBER WHILE PANICKING ABOUT THE DANGER OF BEING HIT. THERE IS NO AUTOMATIC WAY TO RESTART IN CASE OF ACCIDENTAL SHUT OFF. THIS SHOULD BE FIXED OR SOMEONE WILL GET HURT OR KILLED. THIS HAS HAPPENED TO ME SEVERAL TIMES ON THE HIGHWAY AND I HAVE BEEN VERY LUCKY NOT TO HAVE BEEN HIT WHILE FIGURING OUT HOW TO RESTART THE VEHICLE. I COMMUTE DAILY INTO BOSTON AND HAVE TO KEEP EYES ON THE ROAD AT ALL TIMES; WITH THE MODE BUTTON NEXT TO THE POWER BUTTON, THERE IS CONSTANT DANGER OF SHUTTING THE CAR DOWN AT PRECISELY THE MOMENT WHEN I EXPECT AND NEED TO BE ACCELERATING.