Idk if this is company-wide or based on your region or local, but we're told not to exceed 3mph when backing. I first heard about it at Integrad, though.
They were so serious about it. Yeah, the helper's supposed to get out and spot every back (every. single. one.) The helper didn't get a warning letter.... he got fired, man. They wrapped up that observation by telling me to take him back to his car because he's proven he can't work safely and as a result could no longer be a UPS employee. The back that he didn't spot? A 3-point turn (more like a 7-point turn really) at the bottom of a dead ending street of townhouses. It was super tight and I was going forward 6 inches, back 6 inches, forward 6 inches, back 6 inches until I was turned around.
It was bull*, dude.
I'm pretty sure all these petty little backing rules are to keep us from backing at all.