The TCDD – Türkiye Devlet Demir Yollarý (Turkish State Railways) possess 10,984 km of 1,435 mm (4 ft 8 1⁄2 in) gauge, of which 2,336 km are electrified (2005)[1]. (Map)

In 2004, Marmaray project started on a rail tunnel under the Bosphorus straits.

Between Istanbul and Ankara, a high speed railroad line is being constructed now next to the normal speed railroad which is being renovated. When finished, travel time between the two major cities will reduce from 6,5 hours to 3 hours and 10 minutes, using trains ordered from Spain that can reach up to 250 km/h. Construction of a high speed railroad line between Ankara and Konya is also soon to begin in order to connect the two cities with a direct line and reduce travel time from several hours to approximately one hour. Several other high speed and normal railroad projects are currently in the planning stage.

Marmaray Project, one of the biggest projects of the Ministry of Transportation, is a milestone mot only for Istanbul , but also for our country and railways.

Marmaray Project, which is implemented by the Ministry of Transportation, Directorate-General for the Construction of Railways, Seaports and Airports, is a project that is suitable for the history, environment, and cultural heritage of Istanbul . Marmaray Project, as the project of the century and the construction of which still continues at a quick pace, will not harm our Istanbul and will not disfigure it while connecting Asia and Europe with iron networks.

Within the framework of this project, which aims to find a radical solution for the local transportation problem of Istanbul with a mass transportation formula, an uninterrupted aboveground metro line of 76.3 km will be constructed from Halkali in European side to Gebze in Anatolia side that will be modern, high capacity, fast, environment friendly, not harming the historical structure, and integrated with the other transportation systems.

However, Marmaray is of vital importance not only for radically solving the local transportation problem of Istanbul as a world city, but also for protecting the historical and scenic beauties of Istanbul, for developing the railroad transport system, and for the strategic position of our country. Marmaray, which is an important taken for harmonizing with the high speed train lines of European Uninon, will provide an uninterrupted, fast, and economical railroad connection from Europe to Asia, from west to east together with the implementation of the projects like Ankara-Istanbul High Speed Train and Kars-Tbilisi Projects.

text from the official TCDD web site