^Ferreira, Robert; Tharcisiu Alves. (January 2012). "São Paulo Metro". www.nycsubway.org. www.nycsubway.org. Archived from the original on 2014-02-02. Retrieved 2014-02-02. On Lines 1, 2 and 3, the track gauge is a non standard 1600 mm, the third rail is 750 V DC and under running. For Lines 4 and 5, the track gauge is 1435 mm and they use overhead pantograph, precluding any connection to the rest of the system, plus the 4 and 5 lines can't connect because the trains on the 4 line use drive-less technology while trains on 5 line are OPTO. Lines 7, 8, 9, 10, 11 and 12 (operated by CPTM) are all 1600mm and use overhead pantograph.