Azienda Trasporti Milanesi (ATM) is the Milanese municipal transport company; it operates 4 metro lines, 18 tram lines, 131 bus lines, 4 trolleybus lines, and 1 people mover line, carrying about 776 million passengers in 2018.
Overall the network covers nearly 1,500 km (932 mi) reaching 46 municipalities. Besides public transport, ATM manages the interchange parking lots and other transport services including bike sharing and carsharing systems.