Why is my car turning off during driving?

Well it depends on what is happening right before it shuts off. Could be aldenator, map senser,o2 senser... Find someone with a SCAN TOOL, bigger body shops will have this tool it is a more expensive machine that you have to buy cartridges for so not all smaller shops have. It will scan your system and send out codes that will tell the person what is wrong with it.

Is it a hybrid? If it is, it is probably just acting up (a Hybrid automatically shuts off at stop lights, but should start right back up once you try driving) , or maybe it is low on gas. Something might be wrong with your car, so you might want to go find someone with more experience, like a car dealer or engineer. Also, as I already mentioned, your car might be extremely low on gas. The best thing to do is probably just to go to an engineer, car dealer, or someone who knows a lot about cars, and knows about your model of car as well as all the parts. Maybe they can fix it.

Sorry, I wish I knew more about cars so I could be more of a help!