Mapping in progress construction from google maps is fun. First one was Watari Tunnel (渡島トンネル). Here's Nifuku Tunnel (二股トンネル), Bifuka Tunnel (碧雲トンネル), Notaguchi Tunnel (野田追トンネル) and after Yakumo Tateishi Tunnel (立岩トンネル).
Remaining are Asari Tunnel (朝里トンネル), which got just finished digging in November so one exit isn't even on Google Maps and Sapporo Tunnel (札幌トンネル) which has the least progress done and I can only find one tunnel entry point and one section entry point
Also I'm a retard, the spots I labeled as ventilation or exploration shafts are entry points for various sections of the tunnel. Also also, the names might be wrong cuz LLMs and all that.
@Mr_NutterButter I watched an Abroad In Japan video riding the shinkansen, checked the stops on Google Maps, decided to scroll the entire line and noticed there's construction in progress