Six hundred thousand riders a day through a tunnel under the strait, high-speed trains pulling Ankara into orbit — Istanbul’s rail node, on two continents at once.
Istanbul’s rail story is a tunnel under the Bosphorus that turned two continents into one commute — and a high-speed network quietly rewiring Anatolia around the capital’s orbit.
Marmaray carries at least 600,000 passengers a day across its 76.6-km Halkalı–Gebze line — one of Türkiye’s most heavily used public-transport systems — diving under the Bosphorus in a submerged tube that makes the Europe–Asia crossing a four-minute formality.
Demand keeps outgrowing service: from May 2026 late-night trains run seven days a week, with timed transfers to intercity and high-speed services — a small policy change that says everything about the load factor.
The intercity layer: YHT high-speed trains link Istanbul to Ankara in about 4.5 hours and Konya in a similar window, with Söğütlüçeşme on the Asian side functioning as the city’s true intercity railhead.
The metro grid is expanding toward both airports — the M11 line ties Gayrettepe to Istanbul Airport, and Sabiha Gökçen’s M4 extension put the Asian airport on rails as well.
The strategic frame: Marmaray is also a freight corridor — the tunnel sits on the China–Europe middle-corridor logic, where containers and commuters share the same Bosphorus crossing.
Every megacity has one piece of infrastructure that changed its psychology, and Istanbul’s is a tunnel. Before Marmaray, the Bosphorus was a beautiful inconvenience; after it, the city is one labor market with a strait for scenery. Six hundred thousand daily riders made that verdict, and the high-speed lines eastward are extending it: Ankara is now closer to Istanbul in time than most of Istanbul is to itself in traffic.
Next in this file
Subscribe to the digest and receive key market signals every two weeks.