Looking for Info on I-81 in Virginia

[Montana_398]

Good Morning,
Our daughter and her boyfriend are heading out tomorrow towing a travel trailer (not a Montana) - destination the Talledaga Raceway in Alabama. They plan on stopping somewhere along I-81 in Virginia the first night, probably somewhere around Roanoke area. I was wondering if any of you experienced RVers have any suggestions or warnings about travel plaza camping, or any campgrounds that are easy and fast (and cheap). I'm a nervous mother worried about these inexperienced travelers, and any help would be welcomed.

Thanks.
Mrs. Vermonter

Vermonter
Steve and Beth Dow
Middlebury, Vermont
2001 325RK Montana
2002 Chevy Duramax Diesel