Istanbul Underground

The Istanbul underground line between Kadikoy and Kartal forms part of a series of works planned by the city authorities to resolve urban congestion, with special focus on links between the two sides of the Bosporus. Specifically, the new underground line built by Astaldi, measuring almost 22km, links Kadikoy, the area where ferries dock on the Asian side of the Bosporus, to Kartal station (along the E5/D100 motorway). The route, which runs completely underground, cuts across highly populated residential areas and it is able to transport 70,000 passengers per hour, equal to approximately 100 buses or 4,300 minibuses that are extremely popular in Turkey's main cities. 120 trains will travel along the Kadikoy-Kartal line, with a planned maximum speed of 80km per hour.

The tunnels have been excavated using the traditional method as well as with the help of TBMs while the links between tunnels and junctions  will be built using the Austrian method (NATM). Specific attention have been paid to the first section of the line from Kadikoy where, considering the city's age-old history, there was a real possibility of uncovering archaeological finds.

The new underground line have been opened to the public in August 2012.