Do you guys park on busy main roads with multiple lanes of traffic?

I find that I waste a lot of time pulling into customers' driveways and having to back out or turn around. If it's a neighborhood or a back road I'll usually just park on the street depending on the length of the driveway. I haven't done it for customers who live off of those super busy multi-lane roads but I'm super tempted to try it.

I deliver mostly in rural areas and in a lot of the towns, there'll be a big main road or highway with a bunch of small houses on it. Those houses often have tiny driveways and there usually isn't enough space to turn around without hitting something, so I end up having to reverse onto the main road at less than 4 mph which I'll admit is pretty nerve-racking. Especially yesterday when I had a busted up van with no rear view at all, just side mirrors. What's your general rule of thumb?