The northern light rail line, inaugurated in 2003, has a length of 3.5 km and links piazzale Maciacchini to Parco Nord, at the border of the municipality of Bresso.

The line consists of a complete reconstruction of the corresponding section of the Milan-Desio interurban tram line. The light rail line serves the “Valassina” route, which runs through the densely populated area of Niguarda and to the hospital bearing the same name.