M11 (Istanbul Metro)
Line M11, officially referred to as the M11 Gayrettepe–Istanbul Airport–Halkalı Metro Line (), is a rapid transit line of the Istanbul Metro, currently under construction in Istanbul, Turkey. The Kağıthane — Istanbul Airport portion of the line is currently planned to open in August 2022. The purpose of this line is to provide direct and quick access from the Istanbul Airport in Arnavutköy to Levent, Istanbul's main commercial center and to Halkalı, the city's one of the most important train stations. Unlike other metro lines, the M11 will be a limited stop service, meaning that  stations will be spaced further apart. This is most noticeable towards the line's southern ends, where the M11 will only have seven stations within Istanbul's urban area: Halkalı, Tema Park, Olimpiyat, Kayaşehir and Fenertepe in the west and Gayrettepe and Kağıthane in the east. It will have two legs, one from Gayrettepe to Istanbul Airport line and the second from Halkalı to Istanbul Airport line. The first leg of the rapid transit line will be long with nine stations. The second leg of the line will be long with seven stations, in a total of with sixteen stations . The travel time between the end stations will be 60 minutes at a maximum speed of . The line will run through five districts of Istanbul, Şişli, Eyüp, Arnavutköy, Başakşehir and Küçükçekmece. It is expected that the line will carry annually around 94 million passengers. The M11 line will connect to other rapid transit lines: Marmaray, M1, M2, M3, M7 (twice), M9 and at the airport to the high-speed train line. The investment budget of the construction is 999.8 million. The Turkish construction consortium Kolin-Şenbay won the tender for the building of the metro line in December 2016. The  line was not scheduled to be completed before the airport's official October 29, 2018 airport opening. Stations. The M11 has a total of sixteen stations. Out of these sixteen, only seven are within the Istanbul urban area.