From a safety engineering standpoint, handoff is a very, very bad idea. When you automate the common operation of a system, how is the operator supposed to get a feeling for the system? And when the operator doesn&#x27;t handle the system regularly, how is he supposed to handle a situation that&#x27;s so dangerous and unusual that the automation can&#x27;t handle it?<p>If you have years of experience driving a car, maybe it&#x27;ll work. For some time. But what if your last manual intervention was five years ago? Or twenty years ago? The rarer handoff happens, the more stress it puts on the manual operator, and the more likely things go wrong.<p>It&#x27;s much better to have a safe default reaction (stop the car, shut down the reactor, ...) that kicks in when normal, automatic operation can&#x27;t continue.