The first 9.6 km section, 15 station VAL subway opened in 2006 and runs completely underground from Porta Nuova station
via Porta Susa to Collegno.
A 6 station, 3.9 km southern extension from Porta Nuova to
Ligotto opened in 2011, bring the line to 13.2 km with 21 stations. A two station southwest extension
is under construction , and a 3.4 km extension to Line 1 is expected to begin construction in 2016. Two additional lines, all underground, are in the planning stages, including a 19 km southern extension that is expected to be completed in 2015.