Why do you need an atlas?

Question from Dealvion:
Why do you need an atlas?

Answer:
Well you don’t necessarily need an atlas, but a set of paper maps of the area you’re going to have to navigate will be essential. The nice thing about an atlas is that it has maps in it that you may not have known you would need. We’re talking about surviving a civilization ending catastrophic event here. During the chaos of trying to escape is not a time to figure out if you’ve got the correct maps handy (or to try and find a place to obtain the ones you need). If the grid goes down, there will be no GPS navigation available. Be prepared for the worst and hope for the best.