It’s a railway that connects Grodzisk Mazowiecki with Zawiercie that goes through Mazowsze, Łodzkie, Świetokrzyskie and Silesia provinces. It’s almost 224 km long. It’s also a part of international E-65 railway line.
It was built in 1971-1977 and its initial aim was to facilitate cargo transport. During the construction, special geometric parameters were used in order to allow the line to hold trains going up to 250 kph in the future.
It’s the main connection between Warsaw and Upper Silesia and between Warsaw and Cracow. The fastest one too. Trains that go slower than 120 kph can’t use it which is a great idea. Right now it’s ready for trains that go as fast as 250 kph.