Warsaw begins extensive geological drilling for new M4 metro line

Geological teams have started drilling in the Białołęka district of Warsaw, targeting the intersection of Modlińska and Płochocińska streets, as part of preparations for the city's planned fourth metro line (M4). The work involves drill rigs and ground‑probing sondes, with boreholes reaching depths of up to 52 m. In total, the program plans 963 drillings, about 330 of them in Białołęka, alongside roughly 1,000 sondings, 90 research nodes, 50 trial sondings and a series of geophysical and laboratory tests.

The effort, described by Mayor Rafał Trzaskowski as essential for selecting appropriate construction technologies, ensuring safety and minimising impact on the surrounding area, represents roughly one‑quarter of the planned investigations and is scheduled to conclude in autumn 2027. The M4 line will extend over 26 km with 23 stations, linking Białołęka to Wilanów across nine Warsaw districts, while a conceptual design for the line is being prepared concurrently.