Sounds interesting. But you may want to look at online resources and other apps to see if they do not currently offer the information you are looking to provide. I am not sure how much traction your book/app would have though. There are so many travel books and apps now that your offering may get lost in the noise of the other offerings.

Perhaps, you could try partnering with existing sites/apps/books to offer this sort of information that they could incorporate into their offering. You would need to show how the experience would be for the users as well as how your information would add value.