M4 (Warsaw)

The M4 line is the planned fourth line of the Warsaw Metro. It will have a length of approximately 26 kilometers (16 mi) and will consist of 23 stations, linking Wilanów with Tarchomin. It will also include a new metro depot, STP Polfa. The line will be an important element of the metro network and the overall transport system in Warsaw. According to initial findings, it is expected to be used by up to 30,000 people per hour. It will connect the districts of Białołęka, Bielany, Żoliborz, Śródmieście, Wola, Ochota, Włochy, Mokotów, and Wilanów, as well as enable interchange to M1, M2, M3, and M5 metro lines and the main public transport lines: trams, buses, and railways. Upon its completion, M4 is planned to be the longest line in the Warsaw Metro system.