Railroad Ink: Epic & Giant Boards SetExpansion

From BoardGameGeek:

Dive into a new adventure with the Epic & Giant boards! These double-sided special boards allow you to further expand your game experience. The 11×11 Epic board introduces more space to build your networks, trying to connect even more Exits and bypass Mountains that block your path! The 9×9 Giant board let you play with either the Classic or Challenge dice set, and play with two different expansions together, on a whole new scale! Each set contains 4 double-sided boards. To play with the Epic board, you need 6 basic Route dice, so two copies of the game are needed. -description from the publisher