To travel by train in Turkey was sometimes a pain in the ass. Because of the winding route and the outdated railtracks, the speed of the train often could not exceed 60km/h, which means it would take more than twice the time required by bus to travel from Sivas to Ankara. A few years ago, a series of fatal rail accidents tarnished the already shaky reputation of Turkey's state-owned railways even further. A while ago, when I decided to take an overnight sleeper train when travelling from Ankara to Adana, all friends who heard about that shook their head in disbelief, as most Turks consider travelling by train far too slow and inefficient than going by bus or by car. To make it more complicated, in the last few years many sections of the Turkish rail systems were closed due to rail upgrading works, which makes rail travel even more inconvenient and unappealing to the general public. Granted, train fares in Turkey are much cheaper than bus fares, but given the amount of time required and the frequent delay, unless one has a lot of free time on hand and does not need to be in a particular place at a particular time, it is better to go by bus or air.
Well aware of the fact that the Turkish rail system is seriously out of date and under-invested, the Turkish government approved an ambitious scheme to connect virtually all important cities in Turkey with modern high-speed rail networks. The first high-speed line to be built is the Istanbul-Eskisehir-Ankara line, but for whatever reasons, the construction of the line takes ages and is still going on at the time of writing (January 2012). Hence only the high-speed section between Ankara and Eskisehir has entered into full-time service, operated by real high speed trains. Istanbul-bound passengers have to get off the high speed train in Eskisehir and change onto conventional trains in order to continue their journey to Istanbul.