EVERY operator should be held accountable for the operation of his lift and any accidents he has on it.
ways to help keep him in check?
slow the lifts down, set the max speed to a slower rate if it is adjustable on the machine, if not then as has been suggested, install a speed limiter on it.
Putting a wireless collison system or shockwatch impact manager is kinda redundant being that he is trying to prevent the collision before it happens. But none the less if the operator thinks he is being watched or recorded by the device on the lift then he will be more conscientious of how he drives and have less incidents.

As far as wireless speed managers how well do they actually work? I have not had any exposure to these yet. How much do they cost and how accurate and dependable are they?
From a sales standpoint i'm sure i'll hear the usually hype but i want to know the real deal on them from warranty returns, failure rates, etc.

in the end i think usually what works best is to slow the lifts down.