Transportation sector is one of the major emitters of greenhouse gases due to high consumption of fossil fuels in passenger and freight transportation. In recent years, high speed rail systems (HSR) have become an important policy option for intercity transportation in many countries, including Turkey, as they have relatively low emissions impact. Currently, the total HSR network in Turkey extends to 1213 km and connects 7 cities mostly located along a main HSR corridor. Annual ridership of the first two lines, Ankara-Eski ehir (ANK-ESK) and Ankara-Konya (ANK-KON), have reached almost 2 million passengers each, while total ridership in all four lines was about 3.5 million passengers in 2014. With the upcoming two new HSR lines, total length of HSR network will exceed 3000 km by 2020.