Harrisonburg is a fair amount west (obviously not as far as California) and a little north of Richmond, as I am sure you already know.
I have been there many times.
Have been on 42 a number of times also.
If I81 was not there then, wasn't 11S to 60W not a better route?
I guess I64 was not there then either?
I worked in Charleston WV for a while and took just about every route from Richmond to Charleston that was on the map trying to find the fastest way. Man what a bunch of cowpaths I travelled. There simply is no fast way.
As far as I81, I avoid it at all costs. I literally hate that road. Bumper to bumper 18 wheelers in all lanes. It should be four lanes in both directions and it is mostly only two.