Main line trains are given by locomotive-hauled trains. Service frequency is mostly once a day.
In addition to standard carriages (Pulman), couchette cars (Örtülü Kuşetli) and/or sleepers (Yataklı) and restaurant cars are available on overnight trains. Sleepers are generally full on the day of travel, prior reservation/ticketing is advised.
Although it’s easier to find seats in standard carriages, trains are full on special dates (during the first and last days of public holidays). Online ticketing is possible 15 days prior to day of travel. Refund and change is possible.