Yüksek Hızlı Tren

Istanbul and Ankara are Turkey's largest two cities, having a combined population over 16,500,000. Transportation between the two cities is high. The Otoyol 4 motorway is a major highway between the two cities, and the Ankara–Istanbul route is the busiest domestic air route in the country. The route between Istanbul and Ankara by rail has been a single-track line, and trains usually were delayed 30 minutes to 2 hours plus the average 7 hours, 30 minutes travel time. Rail transport in Turkey was already at its lowest point, so in 2003 the State Railways and the Turkish Ministry of Transport made an agreement to build a 533 km (331 mi) line between the two cities. The line would be an electrified double trackline. Construction began in 2004 from Esenkent to Eskişehir. The line was completed on April 23, 2007.[8]

An ETR 500 train set was used for testing the high-speed lines

On February 28, 2007, TCDD requested bids for high-speed train sets from other networks to be tested on the completed portion of the high-speed line.

On March 30, 2007, TCDD signed an agreement with Trenitalia of Ferrovie dello Stato to rent an ETR 500 train set for 4 months.[8][9]

The first run was from Haydarpaşa Terminal in Istanbul to the Central Station in Ankara, using the completed portion of the high-speed line between Hasanbey and Esenkent.

On September 14, 2007, the ETR 500 Y2 set a speed record in Turkey, reaching 303 km/h (188.3 mph).[10] This test received extensive media coverage in Turkey.

On November 20, 2007, the first TCDD HT65000 high-speed train sets purchased from CAF of Spain entered Turkey from the Kapıkule border station in Edirne,[11] and tests were subsequently made with these trains prior to the commencement of services on March 13, 2009.

In 2010 one of the YHT trains was converted into a test train in order to test and measure the new lines.[12] The Transportation Ministry spent 14 million TL (around 7 million Euros at that time) for the installation of testing and measuring equipment on the train, which it named – because it is a tradition to give a name to test trains – as "Piri Reis" after the renowned Turkish admiral and cartographer who drew some of the most accurate and detailed maps of the Mediterranean Sea and the Americas in the early 16th century.[12]

TCDD requested bids for the name of the high-speed service. Out of over 100 entries, the ones with the highest votes were: Türk Yıldızı (Turkish Star), Turkuaz (Turquoise), Yüksek Hızlı Tren (High Speed Train), Çelik Kanat (Steel Wing) and Yıldırım (Lightning). TCDD chose Yüksek Hızlı Tren to be the name of the service.[13]

On March 13, 2009, the inaugural ceremony took place in Ankara; attended by President Abdullah Gül, Prime Minister Recep Tayyip Erdoğan, and Minister of Transport Binali Yıldırım, who started the first phase of the YHT service between Ankara and Eskişehir.

Ankara to Eskişehir service was the first YHT and high-speed rail route in Turkey, entering service on 13 March 2009. The route has the most frequent train service of the whole YHT network, with 13 daily trains in each direction, 8 of which continue to Istanbul, while only 5 daily trains operate just between the two cities. The average journey time is 1 hour and 29 minutes.

Before the YHT came into operation, average journey time between İstanbul and Ankara was 7 hours and 30 minutes. By transferring from the YHT to intercity trains at Eskişehir, average journey time between İstanbul and Ankara has fallen to 5 hours and 30 minutes.[14] After the completion of the second phase of the Ankara-Istanbul high-speed railway (Eskişehir-Istanbul) in 2013, some journeys between Ankara and Eskişehir were extended to Istanbul and YHT started running on the Ankara-Istanbul (Pendik) route on 26 July 2014. The journey is now reduced to as little as 3 hours 49 minutes.[1]

The route was put into service on 23 August 2011 on the second high-speed railway line being constructed in Turkey. With its inauguration, the journey time between these two cities hugely decreased (mainly because of the absence of direct railway link between the cities).

The line was put into service on 17 December 2014. It stops at every stations on its route in which YHT service in present. The average journey time is about 4 hours and 17 minutes.

Ankara to Sivas high-speed rail service is expected to begin operation in mid-2020. The 467 km (290 mi) route will reduce travel time between the two cities from 9 hours and 30 minutes to 2 hours and 50 minutes. The railway will use a straighter route to Sivas, through Yozgat, bypassing Kayseri. Direct service from Istanbul to Sivas is also planned upon opening with an expected journey time of around 5 hours.

Ankara to İzmir high-speed rail service has been talked about since construction of the Ankara-Istanbul high-speed railway began. The 570 km (350 mi) long route will reduce travel time between the two cities from around 13 hours to 3 hours and 30 minutes. The route will diverge off the Polatlı-Konya high-speed railway just south of Polatlı junction and head west, through Afyonkarahisar. The railway will connect to the İzmir-Afyon railway at Manisa and continue into İzmir together with other trains. A second route into İzmir though Kemalpaşa is also planned. This route would diverge off the railway west of Turgutlu and enter İzmir from the east. The line would run underground, parallel with the Halkapınar—Otogar Line of the İzmir Metro, connecting to the existing railway at Halkapınar in the city center.

TCDD HT80000 (Siemens Velaro TR) has a maximum operating speed of 300 km/h (186 mph)[2][4]

The YHT operates at a maximum speed of 300 km/h (186 mph)[2][4] on high-speed tracks. But the YHT also runs on non-high-speed and renewed tracks like the Köseköy-Gebze section of the Ankara–Istanbul high-speed railway where its top speed is 160 km/h (99 mph). Naturally, some speed restrictions also apply in urban sections while accessing the central station, especially in Ankara and Istanbul thus increasing the journey times. The speed on these sections is expected to increase when renewal projects in urban areas (like Başkentray and second phase of Marmaray) will be completed.

A security check point for YHT passengers at the Ankara station

On YHT service, there is usually 1 train engineer (2 on some trains), a train manager (absent in some trips), two train attendants and a café car attendant. Business-class passengers are served meals at their seats if they applied for while buying their tickets. When accessing the trains, passengers must pass a security check like in airports. Maintenance of the sets is done at the Eryaman Yard in Ankara.