Yavuz Sultan Selim Bridge: A Hybrid Structure and Phased Transport Use

The Yavuz Sultan Selim Bridge crosses the northern end of the Bosphorus near its entrance to the Black Sea, connecting Garipçe on the European shore with Poyrazköy on the Asian shore. It is Istanbul's third road bridge across the strait, situated separately from the first bridge completed in 1973 and the Fatih Sultan Mehmet Bridge completed in 1988.

The new bridge forms part of the Northern Marmara Motorway network, serving the planning objective of directing intercontinental traffic toward the north of the metropolis. According to Astaldi's report, average daily traffic in the second half of 2017 was about 43,000 vehicle equivalents; this converted measure should not be treated as a direct count of individual vehicles.

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The scheme was jointly designed by French bridge engineer Michel Virlogeux and Jean-François Klein of Switzerland's T-Ingénierie. Within the project organization, Turkey's IC İçtaş and Italy's Astaldi formed the ICA consortium. The bridge construction contracting chain also included a Korean consortium of Hyundai Engineering & Construction and SK Engineering & Construction, while Gemak participated in manufacturing the steel deck.

Astaldi's 2017 annual report identified the Turkish Ministry of Transport as the client and concession grantor, while listing the operating company separately from the design, procurement and construction contractor. Construction, toll operation and maintenance were distinct responsibilities within the concession project.

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The main span measures 1,408 meters, and the approximately 58.5-meter-wide deck carries eight road lanes on a single level, with space reserved in the center for a double-track railway. Railway loads require control of deck deformation, whereas a long-span suspension system alone could allow substantial vertical deflection under train loads. The designers therefore used stay cables to increase stiffness, combining two load-bearing systems.

Areas close to the towers are supported mainly by stay cables, while the center of the span relies on main cables and hangers, with a transition zone where both systems act together. The main span uses a steel box girder, while the shore-side girder sections and major substructure elements are concrete. Relocating the European tower onto land lengthened the span but avoided some of the uncertainties of constructing foundations in the water.

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Construction began in 2013. The towers were initially built using slipforms, switching to climbing formwork at a height of about 208 meters to accommodate installation of the upper cable anchorage structures. Before all permanent components were in place, temporary transverse bracing helped control the forces and geometry of the tower legs during construction.

Prefabricated steel deck sections arrived on site by ship. Sections near the towers were progressively cantilevered out over the strait and supported by installed stay cables. As the midspan gap narrowed, the remaining sections were erected using lifting equipment supported by the main cables. France's Centre Scientifique et Technique du Bâtiment and the Polytechnic University of Milan participated in wind testing to examine different construction stages. The wide deck, tall towers and still-unclosed structure together increased the demands on lifting operations and wind resistance.

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Astaldi's annual report confirmed that the bridge and the basic road section opened to the public in August 2016; additional motorway sections were still under construction in 2017, the year covered by the report.

A World Bank project document from August 2025 explicitly stated that the bridge had carried road vehicles since 2016 and had the space and load-bearing capacity for a double-track heavy railway, but that the tracks, systems and railway approaches on both sides had not yet been built when the document was prepared. It presented construction of a new line using the space reserved on the existing deck as a subsequent project to improve rail connections across the strait.

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Engineering work during operation continued to focus on structural changes. In a 2018 technical presentation, ICA's Meltem Akyüz described the bridge's 126 sensors: accelerometers tracked vibration characteristics, satellite positioning equipment observed tower and deck displacements, and other instruments measured temperature, inclination, wind conditions and bearing displacement.

These records were brought together through data acquisition nodes to compare actual performance with design expectations and help identify changes caused by long-term aging or exceptional events. The presentation also emphasized routine and special inspections and continuing interpretation of monitoring data.

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