As a kid, my brother and I would travel up (from FL) to PA with my Mema and Papa. We usually took a couple days, but it was lots of fun (when I was not feeling carsick).
Myself driving, my longest road trip was going to a conference just north of Atlanta, GA, by myself.
This summer however, I will probably be driving up to Ridgecrest, SC, and maybe taking some detours to visit peeps. So that will probably be my longest road trip yet, and I will likely drive by myself.