All the map/direction sites say to take the Ohio Turnpike (80) to to Breezewood across PA, then south past DC to Fredericksburg. It seems like there'd be less traffic to go south through OH, then east across W. VA, but maybe that would take longer? Any advice?

Where in Virginia are you headed?

I think the problem is that think aren't a whole lot of east west interstates in WVA. It is really mountainous.
You might be able to come down to Columbus, OH, drop south on US 23 to Portsmouth, a bit east to Charleston WVA and I77 south to Wytheville VA and then east on I81 east to ????? and then Fredricksburg. All those roads are 4 lane or interstate and you can make good time. But this may get you too far south to do you any good. To give you an idea of time, I think from Columbus to Wytheville would be about 6 hours.

When we head to WV from MI for rafting, we take the Ohio Turnpike to I-77. I-64 cuts off to take you to Virginia. [We've done that in the past]. The only problem taking I-64 is that you take a jog north on I-81 before continuing to Richmond.

Another alternate to Fredericksburg Va.

From where ever MI, south to I-80/90 (OH TKP) to exit 118, US-250 south/east thru Milan/Norwalk. Wheeling WV take I-70 to Washington PA. South on I-79, Morgantown WV. East on I-68 and back on I-70 once again. Frederick MD south on US-15 to just south of Warrenton VA, US-17 to Fredericksburg.

This should get you to just about anywhere in the eastern part of VA. If going to the western or central area of the state US-23/I-77/81 or I-64 should be considered.......

That's right==I64. That's what they want.

RedRock's route is what we take from Western Michigan to Virginia Beach. It's like 5 miles longer, 20 minutes shorter, much better roads. immensely less bumps in the road, less traffic. And, if you chose to get off, more to see (not much to see between Pittsburg and Warfordsburg, PA).