My wife have already rented a sweet minivan for our trip to Atlanta next week for Thanksgiving. Lots of room for our cat Walker and dog Hurley and Mountain Dew on ice and ready to keep us awake for the long drive! Like you, the music needs to be mapped out in advance for the perfect playlist. Uswitch (insurance rate comparison site) just dropped a brand new shiny study that can tell you exactly how many rock and roll songs you need for the trip so your ears don't get bored!
For their study, Uswitch looked at the 10 favorite road tips taken in the U.S. as their starting point (many of us actual prefer rock and alternative music for our trips). Google Maps was used to calculate trip duration, then average song length. One example tracked was if you were to travel the entire distance of Route 66 (I love Depeche Mode's cover of that song), you'd need 474 rock and roll songs to cover the trip! Check out the full details of their results HERE.