Originally Posted by
AlmostTrick
Honest question: Why not have a mirror extension on an angle, or a convex spot mirror, to cover some (or all) of that blind spot where you're just relying "primarily on judgement"?
I'd be surprised if there wasn't a convex mirror placed below the mirror shown in the video. I think the OP didn't want to create a distraction from his primary message to cyclists by showing all the tools in the box that truckers have, especially since all too many truck drivers don't seem to know how to use some of their tools.
It's actually difficult to sneak onto the right side of a skilled truck driver unnoticed, but in complex urban situations, it can be done because the driver only has one set of eyes and they can't be on everything at once.