Sirkeci is an underground railway station along the trans-Bosphorus Marmaray tunnel. This underground station was opened on 29 October 2013 along with four other stations (Kazlıçeşme, Yenikapı, Üsküdar and Ayrılık Çeşmesi) on the Marmaray line. Sirkeci is serviced by TCDD trains running between Kazlıçeşme (west of Sirkeci) and Ayrılık Çeşmesi (east of Sirkeci on the Asian side) with 6- to 10-minute intervals. Once the rehabilitation of the existing rail lines are complete, Marmaray commuter service will run west to Halkalı and east to Gebze. This service is expected to commence in 2016.