One time I heard a description of why we drive on which side of the road and the driver sets where. I which I could find a copy of it. It all sounded good; but, whenever I try to reconstruct it I get confused.
I did find this on the web:
Why Some Countries Drive on the Right and Some Countries Drive on the Left
and this
Why do some countries drive on the left and others on the right?
But, why do engineers set on the right and engine drivers set on the left? -- I don't know. Once a practice gets started it is hard to change.
BN