How often do oil trucks spill?

Answer 1

Oil spills occur, everyday! Somewhere in the world just now, an oil spill is happening. :O

Answer 2

Quite often. This is because the drivers are often drunk or high, so the answer to that is a question, How often are oil truck drivers drunk?

Answer 3

Oil spills only happen when oil is accidentally tipped into the ocean. But if there is a war going on the enemies might try to spill oil into the ocean.