I love this book but you need to decide for yourself check it out at the libraryor local bookstore. I found it great because speed limits change on a moment's notice...if you have the book you know this. Driving through Atlanta can be nerve racking when you have 8 lane going in one direction and they suddenly drop down to 6 lucklily we had the book to tell us what lane to be in at which time. Otherwise we could have been headed off to God only knows where. Check it out on line
www.i75online.com. So I guess to answer your question I found this book very helpful. DH lent it to a coworker and she went out and bought her own after her trip. If it is your first time driving down I'd see if you could get your hands on a copy. Although a GPs system is wonderful I don't think it'll tell you what lane you want when driving through Atlanta. It also gives you pointers on were to expect thick fog/ mtn mist. And where they advise you not to have your cruise control because of road conditions and which areas are thick for deer etc.