It seems that new stations are frequently built or rebuilt primarily for Shinkansen in Japan. For example, Shin-Otaru is currently under construction for the Hokkaido Shinkansen, whereas the Shin-Hakodate and Shin-Aomori rebuilds were effectively brand new stations (and they still feel little bit like relatively sparse junction stations).
Why not expand existing stations instead? One exception seems to be Sapporo – there is no "Shin-Sapporo station" planned. What is the explanation for this, as well?
Thank you in advance!
by Lamlash