All the systems in the world, even with redundant safety systems, will fail when a human is in control. Forklifts last on average 8 years, operate many hours a day, in harsh environments and abusive use. Then add on the variance of maintenance quality and there will be failures. In the end it comes down to the judgement of the driver. THere is only one true safe product and that is a robot, in a closed room with no people around.

These systems are a good attempt at making things safer. Accelrometers and other electronics though will fail when bounced enough, not kept in calibration, or just plain fail. How long does your laptop last? Calibration and testing of them is a requirement.

Don't forget users will bypass them - they aren't stupid - somehow - when they think they "get in the way" or "slow" them down.

How many "dead man" swothes have you seen bypassed?