ATAC S.p.A. (Azienda Tramvie e Autobus del Comune di Roma; Tramways and Buses Company of the Municipality of Rome) is an Italian publicly owned company that runs most of the public transport network and the paid parkings in Rome. It manages the entire tram, trolleybus and metro networks of the city and most of the , which is managed also by the private company . In addition ATAC operates also three regional railways, owned by Regione Lazio: Rome-Civita Castellana-Viterbo, Rome-Giardinetti and Rome-Lido.