[grovegames]

I think all three should be used. But this isn't the question being addressed, which is whether to use tractors at all...

[gsylvie]

Even if better training or better documentation is available, how do you get the driver of the tractor to benefit from it?

The solution is better tractors. Don't blame the user.

[dfsegoat]

but why is that question being asked? because of safety / security...