Passengers flying out of Istanbul can now reach the terminals almost entirely by train and metro. The overnight train from Sofia via Plovdiv arrives at Halkalı station, from which metro line M11 runs directly to the airport. The trip from Halkalı to the terminal takes about 30 minutes, according to Turkey's Ministry of Transport.
The connection became possible after the final section of the line — between Halkalı and Arnavutköy — officially opened on June 19, 2026. Passenger service began the following day, June 20. That means the international train from Bulgaria now stops at a station directly linked to the airport line.
Bulgarian State Railways (BDZ) says the Sofia–Halkalı train runs daily and includes Turkish couchette and sleeper cars. The route passes through Plovdiv, Dimitrovgrad and Svilengrad before continuing through Turkey to Istanbul. Passengers boarding in Plovdiv or Dimitrovgrad can also buy tickets straight through to Halkalı. The operator notes that track maintenance work sometimes alters departure times, so travelers are advised to check the schedule on the day of travel.
Under BDZ's current fare table, a one-way second-class ticket from Sofia to Halkalı costs €26.40 for an adult. A seat in a couchette car costs an extra €10. A berth in a two-bed sleeper compartment is €15, while a private sleeper compartment costs €35 — for which a first-class ticket is required. Reservations for sleeper or couchette berths are mandatory. Tickets and reservations can be purchased up to two months in advance, though that window is sometimes shortened due to maintenance work.
The new 22-kilometer section between Halkalı and Arnavutköy closed the last missing link in the Gayrettepe–İstanbul Havalimanı–Halkalı line, which now runs about 69 kilometers in total. According to Turkey's transport ministry, Halkalı station is now also connected to the Marmaray line, high-speed rail services and other city transit routes. On its very first day, the new section carried more than 10,000 passengers, while the line as a whole handled over 44,000 riders that day.
For Bulgarians flying through Istanbul, this removes one of the biggest hassles of the journey. Until now, getting off at Halkalı meant finding a bus, a taxi or some combination of city transit to reach the airport in the northwestern part of the city. Now travelers can simply step off the international train and continue straight to the terminal by rail. It's still wise to build in a comfortable buffer between the train's arrival and flight time, since international rail travel involves border checks and schedules can shift due to ongoing maintenance work.
With the expansion of the M11 line, Halkalı station has become a major transit hub in Istanbul's European side. Besides the international trains from Bulgaria, it now intersects with city rail lines running to various parts of the Turkish metropolis. For travelers from Sofia, Plovdiv and southern Bulgaria, the combination of overnight train plus metro is now a real alternative to driving or taking an intercity bus. The main advantage is that once off the train, the route to the airport continues without having to navigate Istanbul's congested boulevards.