Humans don't handle all corner cases. People can be slow to react to completely novel or surprising situations. There will be corner cases where humans generally do better than a machine, but the simple rule to slow down and come to a halt if things look too weird or confusing will almost always be the right answer.

Ideally, driverless cars will one day be better drivers than humans and this will save tens of thousands of traffic deaths per year. Holding up progress because cars will be confused in extremely rare or improbable situations will cost more lives than it saves.