The Turkish government is planning to build a high-speed rail (HSR) line between Ankara and Istanbul, which will reduce the travel time between the cities from 4 hours and 5 minutes on the existing 533 km line to just 1 hour and 29 minutes. The 344 km planned route is to be designed for a maximum speed of 350 km/h. It will branch off the existing line at Adapazari and run via Sakarya and through the Bolu Mountains to Nallihan and Ankara.
