Milan’s new M4 metro line has come into service with the opening of its first six stops, from the Linate city airport to the Dateo Station. By 2023, it will reach San Babila in the historic centre. Then it will go on to San Cristoforo at the other end of the line. Before the turn of the century, Milan witnessed a lively debate concerning its airports. One vocal group called for the closure of the Linate city airport and the transfer of all flights to Malpensa, the international airport many kilometres away from the city.

Even though the avenue linking Linate with the city centre was perennial clogged with traffic, it remained open thanks to the fervent support of the bankers, entrepreneurs and fashion designers, the last of whom saw the city at the heart of their industry. But Linate’s survival also called for a sustainable means of transport, such as a metro line would connect it with the centre in a mere 15 minutes. It would eventually materialize into the M4, otherwise known as the blue line.

Built by Webuild, this underground line will have driverless trains. It consists of two parallel tunnels – one for each direction – running for 15 kilometres with 21 stations, and 30 offices, deposits and other buildings. With this new line, Milan comes close to Europe and challenges Berlin. “By 2030, we want to expand the metro network from 127 kilometres to nearly 200 kilometres,” said Mayor Beppe Sala. Berlin has a metro with 150 kilometres, and beyond that there is Paris with 227.

The M4 will serve 24,000 passengers every hour in each direction, which means 86 million travellers every year. It will allow for a reduction in traffic by 180,000 vehicles per day and an annual reduction of 75,000 tonnes of CO2 emissions.