Turkey has put the finishing touches on a landmark transit project, completing the last segment of the Gayrettepe-Istanbul Airport-Halkalı Metro Line on Friday. The fully operational 69-kilometer route is now recognized as the nation’s longest and fastest metro line.
President Recep Tayyip Erdoğan presided over the opening ceremony in Istanbul, officially inaugurating the 22-kilometer Halkalı-Arnavutköy section — the project’s final phase. The completion brings the entire underground corridor connecting Gayrettepe, Istanbul Airport, and Halkalı into full service.
Stretching 69 kilometers with 16 stations total, the line reaches top speeds of 120 kilometers per hour, making it Turkey’s fastest metro route and placing it among the world’s lengthiest underground airport rail links.
At the ceremony, Erdoğan spoke to the scale of Istanbul’s growth and connectivity goals. “We are weaving our city, one of the world’s largest metropolises, with a population of 16 million and nearly 20 million annual visitors, stitch by stitch with a network of railways,” he said.
The newly unveiled segment features five stations: Ibn Haldun University, Kayaşehir, Olimpiyatköy, Halkalı Stadium, and Halkalı. Officials noted that around 1.5 million residents living in the Başakşehir and Küçükçekmece districts will now have direct rail access to both Istanbul Airport and the city center.
The metro system runs without drivers and uses the COBALT signaling platform, a technology developed domestically by ASELSAN. Of the 25 train sets assigned to the route, 15 were built to fully autonomous specifications by CRRC.
Turkish government projections suggest the line will produce economic benefits totaling 935 million euros by the year 2043. Additionally, reduced traffic congestion is expected to save commuters and travelers roughly 117 million hours of travel time.
The project was rolled out in phases over several years. Service on the Kağıthane-Istanbul Airport section launched in January 2023, with the Kağıthane-Gayrettepe portion following in January 2024. The Arnavutköy-Istanbul Airport segment came online in March 2024.
With the full line now active, travel times are expected to drop considerably. Riders going between Halkalı and Istanbul Airport should reach their destination in about 30 minutes, while the trip from Gayrettepe to the airport is projected at roughly 35 minutes. End-to-end travel between Halkalı and Gayrettepe is estimated at 57 minutes.
The metro line also connects to a broader web of transportation options, including Marmaray commuter rail, high-speed rail services, and several other metro lines throughout the city.
