Milan M4 Blue Line metro extension to open on July 4The extension takes the line to San Babila in Milan city centre. Photo Credit: Hitachi The extension takes the line to San Babila in Milan city centre. Premium Subscription Required You must be a premium subscriber to access this content: View Subscription Options Already a subscriber? Log in here Categories: Europe, Metros, NewsTags: Hitachi, Italy, Milan, Milan Line 4, Premium, WebuildMore on this story Breakthrough for Milan Metro Blue LineSeptember 14, 2020Milan opens first driverless metro lineFebruary 8, 2013 First section of Milan Line M4 opensNovember 28, 2022