Line D4 (Moscow Central Diameters)

D4 (МЦД-4) or Kaluzhsko-Nizhegorodsky Diameter (Калужско-Нижегородский диаметр) (previously known as Kiyevsko-Gorkovsky Diameter (Киевско-Горьковский диаметр) is the fourth line of the Moscow Central Diameters which opened on 9 September 2023.