AIIB Signs $1.5B Financing for Istanbul Rail Crossing

ISTANBUL – The Asian Infrastructure Investment Bank (AIIB) and the Government of Turkiye signed in 2025 the first phase of a financing package of up to USD 1.5 billion for the Istanbul North Rail Crossing (INRAIL), a new double-track, electrified railway between Çayırova on the Asian side and Çatalca on the European side. The 122 km corridor will cross the Bosphorus via the Yavuz Sultan Selim Bridge, designed with space reserved for rail since its 2016 road opening. The line is expected to carry passenger trains at up to 160 km/h and freight trains at 80–120 km/h.

What Is the Full Scope of This Project?

The INRAIL project comprises a new double-track, electrified railway of approximately 122 km—127 km per the AIIB press release—equipped with modern signalling, designed for 160 km/h passenger operations and 80–120 km/h freight operations. The route largely follows the existing motorway corridor between Çayırova and Çatalca but includes tunnels, viaducts and newly built railway sections. It will bypass congested central Istanbul, complement the Marmaray rail tunnel, and create a direct rail link between Istanbul Airport and Sabiha Gökçen Airport. Project documentation estimates total cost at approximately USD 8.27 billion. Once operational, freight transit between the two points is expected to fall from about 13 hours to 3.6 hours, and airport-to-airport public transport journey time from 120 minutes to 65 minutes. The project is expected to reduce emissions by about 16 million tonnes of CO₂ equivalent over the analysed operational period. The World Bank has classified the project as one with substantial social and environmental risks; it will affect 53 localities in Istanbul and Kocaeli, requiring compensation, resettlement and livelihood protection plans.

Key Project Data

Note: Independent verification of a named design-build contractor and final completion date was not available at time of publication.

How Does This Compare to Similar Projects?

At USD 8.27 billion, INRAIL is 48% larger than the USD 5.6 billion Dubai Metro Blue Line contract awarded in December 2024 and 22% smaller than the USD 10.61 billion Second Chengdu-Chongqing high-speed railway investment (Source: Rail market comparison dataset, 2025). The comparison highlights INRAIL’s position as a mid-size capital project globally but one of Turkiye’s largest rail undertakings. Unlike the Dubai metro contract, which focuses on urban rapid transit, INRAIL is a mainline corridor combining freight, intercity and airport traffic.

Editor’s Analysis

INRAIL converts a road-bridge crossing into a two-corridor rail solution for Istanbul, but its main operational bet is freight decongestion rather than airport passenger volume alone. The 13-hour to 3.6-hour freight time saving is the clearest capacity signal for logistics operators using the Bosphorus route. In the 2025 signalling market, Europe’s lead is driven by modernisation of existing corridors, and INRAIL’s greenfield signalling package may compete for the same digital and automated freight technologies that Alstom, Hitachi and CRRC are deploying elsewhere (Source: Railmarket News, 2025).

FAQ

Q: How much is AIIB providing for the Istanbul North Rail Crossing?
A: The AIIB has signed the first phase of a financing package of up to USD 1.5 billion for INRAIL; the total project cost is estimated at USD 8.27 billion.

Q: What route will the new railway take between Istanbul’s airports?
A: It runs between Çayırova on the Asian side and Çatalca on the European side, crossing the Bosphorus via the Yavuz Sultan Selim Bridge, and will cut public transport journey times between Istanbul Airport and Sabiha Gökçen from about 120 minutes to 65 minutes.

Q: When will INRAIL be completed?
A: No completion date was officially disclosed in the project documentation or AIIB announcement.