Milan, M4 line: the subway linking the airport to the city center

The first train departs around 10:30 in the morning. Onboard are journalists and representatives of institutions, but above all the workforce: workers, technicians, and engineers representing the more than one thousand people who have worked in the construction sites of M4, the subway line that cuts through Milan from East to West. They are embarking on a 12-minute journey, the time it takes to reach San Babila from Linate Airport, a small revolution in urban transport that will be celebrated on July 4th with the opening of two new stations: Tricolore and San Babila, the historical and economic heart of the Lombard capital.

What is being delivered is the subway for the citizens (which is why the Municipality has decided that the rides would be free for everyone on the first day of operation), a unique project carried out by the Webuild Group, which sees San Babila not as a destination but as a crucial stage of a journey that is still partly unwritten.

In total, there will be 21 stations along the 15-kilometer line, and after San Babila, there will be Sforza Policlinico, Santa Sofia, Vetra, De Amicis, and Sant’Ambrogio, all central stations, and then onward to the opposite terminus of San Cristoforo where the journey of the new M4 will be completed.

The ultimate purpose of M4 lies in its ability to become a logistical accelerator for the city, connecting other subway lines, road transport hubs, and, of course, Linate Airport.

Reducing the travel time between the center of Milan and the city airport to just 12 minutes offers an incredible advantage to the Lombard capital compared to many other European capitals, where connections between the airport and the metropolitan core are slower and more expensive. M4 goes beyond these barriers, but it doesn’t stop there. With its 21 stations, the subway is designed to serve the entire population, from those living in the city center to those residing in the outskirts. Once operational, the line will be capable of transporting 24,000 passengers per direction per hour, with an estimated 86 million passengers using it every year. All of this is made possible by the line’s features, with trains measuring 50 meters in length, driverless locomotives capable of reaching a maximum speed of 80 km/h, and a train frequency of one every 90 seconds.

Once the entire line is inaugurated, there will be 40 trains in operation (47 trains planned to be available) traveling beneath the city of Milan.

After the opening of the first section between Linate and Dateo, M4 now also welcomes the commissioning of the Tricolore and San Babila stations, a great achievement for a complex project carried out in the city center with high engineering complexity.

Underground excavations have been accompanied by the objective of transforming the line into an opportunity to redevelop many areas of the city. This has already happened in the first section near Dateo, where new urban parks, pedestrian and bicycle paths, spaces dedicated to children and the elderly have been created around the new stops. Similarly, for Tricolore and San Babila, the construction of the stations was accompanied by a complete redesign of the surrounding areas, with pedestrianization of new spaces, the creation of green areas, and the use of elegant materials such as natural stone and glass. Additionally, Piazza San Babila has been completely closed to traffic, transforming into a place of urban gathering in continuity with the urban space created by architect Luigi Caccia Dominioni.

Sustainability, urban redevelopment, urban mobility: M4 encompasses all of these elements, an achievement made possible by the work carried out in these years (and still ongoing in the new stations) coordinated by the Webuild Group, managing dozens of construction sites and complex excavation operations, such as those beneath the monumental buildings of the historic center. This commitment can now be summarized with numbers: 950,000 cubic meters of concrete poured, 1.4 million cubic meters of open-air excavation, in addition to the kilometers excavated by the TBM (tunnel boring machines), underground in Milan to allow the subway trains to run.

Today, those trains add another section to their journey, bringing Milan closer to Europe and renewing the promise to citizens of soon reaching the opposite terminus of San Cristoforo.