As well as a specialised Route 66 guidebook/map you should definitely take an up-to-date road atlas too to make sure you’re always heading in the right direction. If you plan on taking any side-trips off Route 66 then a modern map is essential to avoid getting lost.
Although Route 66 isn’t featured on modern maps, an up-to-date atlas will still be able to give a general idea of where you are in relation to the major roads.
