Entrance to Alaska's Whittier Tunnel, a unique 4km tunnel that uses scheduling to share a single lane between both road vehicles and trains [1024x768] : r/InfrastructurePorn
Whittier (Alaska) – Travel guide at Wikivoyage
Portage Glacier Highway - Wikipedia
File:Whittier-Tunnel-Interior-With-Safe-House-2008-May-31.jpg - Wikipedia
City of Whittier – Gateway to Western Prince William Sound
Virtual Drive, Whittier Tunnel, Transportation & Public Facilities, State of Alaska