@Ron-Block, I guess you are talking about updating, not downloading (fisrt time). But you are right, when updating the app does a re-download of all previously downloaded maps. Downloading that much information at once is prone to errors, like you are experiencing. The (simple) advice is to download only the states you really need 
. What helps the download to complete is to leave your phone alone while downloading and don't do other things with it simultaneously. Don't have it switch between networks ahile the download runs.
To comfort you, I can tell that an interrupted download will continue where it left off if you restart the download. It just takes a moment for the app to index what it already has downloaded earlier.
Hopefully sometime in the future the update will be smart enough to only download deltas (changes between the current and the new map segments).
