If you are taking I-81, I would recommend staying in Harrisonburg, VA (home to James Madison University). It is a very nice little college town so if you want to kick around in the evening, they have some cute little restaurants. There are 3 Harrisonburg exits directly off I-81 so you don't have to travel far off the interstate. It's safe too. Now, if you are going while school is in session it can be quite busy, but otherwise, I really enjoy the place. Sorry that my son graduated. Harrisonburg is about 2 hours south and west of DC. You'd probably have an 8 hour drive to Massachusetts the next day.