I was trained to use the driver side when delivering a single package resi that is on the opposite side of the street. I realize it isn't the correct method .NOW, but as a rookie(and a few years after) I did it all the time.
Not being a driver, I don't know what the methods say, but what if you're delivering on a one-way street to someplace on the left?
There's a bread compnay around here that doesn't even have a drivers side door on their step-vans, and I've wondered what they do at grocery stores and restaurants where the loading dock has a wall on the right. Or what they'd do if they were in an accident that made the right-side door inaccessable. (They can't walk-thru to the back because the racks are wall-to-wall.