New information leaked on Fallout 4! The map size is supposedly two to three times larger than Fallout 3 and even larger than Elder Scrolls V:Skyrim.
Check out these links for more Fallout 4 information and click the link at the bottom for the original article.
https://doddthoughts.wordpress.com/2015/11/04/bethesda-releases-more-fallout-4-screenshots/
https://doddthoughts.wordpress.com/2015/11/01/massive-fallout-4-gameplay-details-leak/
Source: Fallout 4 World Map Compared With Fallout 3, Takes 11 Minutes To Traverse In Game
Doddthoughts 