Central Railway Main Line (CMK) - the key railway line in Poland | PolishTrains

At a glance

• The CMK (line no. 4) runs 223.8 km from Grodzisk Mazowiecki to Zawiercie
• The line was designed in 1970-71 for speeds of 200-250 km/h, making it visionary at the time
• Passenger services on the CMK began in 1984, with InterCity trains added in 1992
• Pendolino ED250 and EIC trains use the CMK for the fastest Warsaw-Krakow connections
• ETCS Level 2 modernisation on the Korytow-Zawiercie section costs around 361 million PLN
• Trains are scheduled to reach 250 km/h on the CMK by December 2027

The Central Railway Main Line (CMK) enables thousands of passengers to travel quickly and comfortably between the north and south of the country every day. It is thanks to the CMK that trains running between Warsaw and Cracow, Katowice or Wrocław are able to reach record speeds, resulting in shorter journey times and greater comfort for travellers.

Modernisation of the CMK opens up new possibilities for the development of railways in Poland, contributing to an even better quality of services and the competitiveness of rail transport. Why is the central trunk line so important and how will it change in the coming years? You will find all the information in the rest of this article.

In the second half of the 1950s, a capacity deficit between Silesia and the northern and central parts of Poland restricted the country's development. In response to this challenge, work began on the concept of an efficient connection between these regions.

Between 1970 and 1971, the Central Railway Line was designed, adapting it to speeds of 200-250 km/h - a truly visionary approach at the time.

Large curve radii (4,000 m) were used in the construction of the trunk line, as well as the appropriate distance between track centres (4.5 m). All this was intended to ensure maximum safety for the trainsets when reaching high speeds.

The first passenger trains started running on the CMK in 1984, reaching a maximum speed of 140 km/h. In 1988, trainsets developed to a speed of 160 km/h. The result? A significant step in the development of the Polish railway - just compare the speed of the trains:

• A train journey between Warsaw and Katowice in 1983/1984 took 4 hours 6 minutes, in 1984/1985 3 hours, in 1985/1986 2 hours 58 minutes and in 2025 is 2 hours 25 minutes.

• A train journey between Katowice and Warsaw in 1983/1984 took 4 hrs 31 mins, in 1984/1985 3 hrs 4 mins, in 1985/1986 2 hrs 58 mins and in 2025 is 2 hrs 30 mins.

• A train journey between Warsaw and Cracow in 1983/1984 took 4 hours 29 mins, in 1984/1985 3 hours 11 mins, in 1985/1986 3 hours 4 mins, and in 2025 is 2 hours 19 mins.

• A train journey between Cracow and Warsaw in 1983/1984 took 4 hours 23 minutes, in 1984/1985 3 hours 18 minutes, in 1985/1986 3 hours 4 minutes and in 2025 is 2 hours 20 minutes.

Thanks to modern technical solutions, the Central Railway Main Line (CMK) has become a "testing ground" for the development of the railway infrastructure in Poland, allowing new rolling stock and technology to be tested. How was it possible to achieve such good journey times? It is a matter of increasingly modern rolling stock, a minimum number of stops, and a small time reserve of only about five minutes for the entire route.

Railway line No. 4, or the Central Railway Main Line, as you already know, plays an important role in the Polish transport system, connecting Warsaw with Cracow, Katowice and Wrocław. In order to meet the increasing transport demands, modernisation works have been initiated to increase the speed of trains and to enhance safety.

One of the most important projects is the construction of a modern ETCS Level 2 rail traffic control system on the 210km Korytów - Zawiercie section. The value of this modernisation is as much as PLN 361 million.

The system is to continuously supervise the driving of the vehicle by the driver, monitoring permissible speed and stopping points, thus contributing to increased safety and rail traffic efficiency.

Work is also underway to adapt the CMK infrastructure for the passage of trains at speeds of up to 250 km/h. These include the replacement of tracks on the Psary - Zawiercie section, the modernisation of the Knapówka branch station (here, turnouts for high speed are being replaced) and the reconstruction of the Zawiercie station, where modern railway traffic control devices have been installed.

These phases of CMK construction and modernisation are to amount to a total of around PLN 1.8 billion. They are financed from budgetary and EU funds under the National Reconstruction and Resilience Plan (KPO).

In order to meet the growing transport requirements and to increase the competitiveness of the railway, further investments and continuous modernisation of railway line No. 4 are planned. One of the main objectives is to raise the maximum speed of trains to 250 km/h. This will significantly reduce travel time between key cities and, as a result, convince Poles to abandon their cars in favour of public transport on the high-speed line.

To this end, work is being carried out, including:

• implementation of modern control systems, such as the Level 2 European Train Control System (ETCS) we have already mentioned, which will ensure the safety of rail traffic,

• modernisation of bridges, viaducts and culverts that are part of the CMK line (railway line No. 4), which aims to improve the railway line's capacity.

As part of the Central Communication Port (CPK) Railway Programme, the construction of a new line is also planned as an extension of the CMK railway line to the north - this is to enable a direct connection to the new airport and integration with other planned High Speed Railway lines.

These investments are aimed at creating a coherent, modern rail network and adapting the central arterial line to meet future transport challenges and contribute to the sustainable development of the country. It is estimated that a maximum speed of 250 km/h for trains on the No. 4 railway line could be achievable as early as the end of 2025!