This will be made possible by the completion of the much-delayed project to rebuild the railway from Gebze via Pendik to Haydarpasa and Ayrilik Çeşmesi to connect with the Marmaray tunnel under the Bosporus, which opened in 2013. The rail link from Sirkeci and Kazliçeşme to Halkali on the European side is also being restored.

The project involved reconstructing the existing double-track line with two tracks for Marmaray commuter trains and one track for main line trains, which will be used by high-speed services during the day and freight at night.

TCDD Transport plans to operate high-speed trains from Ankara and Konya to both the original terminus at Haydarpasa and to Halkali.

The 13.6km Marmaray service between Ayrilik Çeşmesi and Kazliçeşme carried an average of 5.3 million passengers per month in 2017. The extended service to Gebze and Halkali is expected to carry 1.5 million passengers per day and increase rail’s share of urban transport from 12% to 28%.

Freight trains have been using two train ferries to bridge the gap in the rail network through Istanbul.