To avoid the highways it sounds like a great route. I actually have become in favor of US30 to get to a friends home in Downingtown and my dealer for the 5th wheel in West Chester. So much nicer then I95 and barely adds travel time.
I take US15 all the time in the local area and use US29 exclusively to get from my home area to VIR which is just east of Danville, VA. US29 has never been too bad of a run no matter what day I have taken it either. Just be prepared as I said when you reach Charlottesville, VA as the traffic can get pretty thick. You want to stay to the right lanes to continue on US29S and I found that most of the parking lots in the Charlottesville area are not RV friendly, though you can manage them and find parking in some.