fail-safe

“Within moments, the robot came to a full stop in response to sensing a pedestrian in close proximity, which is considered its fail-safe state.”

There’s no 100% safe way to lift 500 pounds, just like there is no fail-safe way of throwing 100 mph.

One significant solution implemented as a fail-safe for Level 4 automated vehicles is the concept of remote driving.

And because airplanes are packed with fail-safes, there are times when a flight with a malfunctioning system can safely proceed simply by relying on one or more backups instead.

This is a fail-safe scenario but the converse "wrong side" failures -- when the signal goes from red to green -- are much more hazardous.