Quote Originally Posted by mansworld View Post
The sign "If you can't see my mirrors I can't see you" this apply when the big vehicle is moving forward. But when moving rearward, the big vehicle needs a human spotter or a rearview camera, because cars and motorcycles behind the big vehicles are limited in their ability to maneuver.
It applies for backing up as well. Also, if the spotter can't be seen in a mirror, they are not of any use...