The Eurasia Tunnel or Istanbul Strait Road Tube Crossing Project is a highway tunnel that connects the Asian and European sides of the Asian and European sides, the foundations of which were laid on February 26, 2011, under the seabed on the route of Kumkapı on Kennedy Street and Koşuyolu on the D-100 Highway and allows the passage of the Bosphorus. The total route is 14,6 kilometers with tunnels and connection roads. It is aimed to reduce the travel time of up to 100 minutes to 5 minutes in heavy traffic between Kumkapı and Koşuyolu.
In order to provide an alternative road crossing with three bridges and a car ferry in the Bosphorus, the project, which was built around 1,2 kilometers south of Marmaray, is expected to provide a more balanced urban transportation to Istanbul by sharing the traffic loads of the existing three bridges and ferryboats. . It is the second underwater tunnel after the Marmaray tube passage in Istanbul. Although the tunnel toll is charged in both directions; For 2017, it was $ 16,60 for cars and $ 24,90 for minibuses. With the raise in 2020, the toll was 36,40 TL for cars and 54,70 TL for minibuses. For the name of the tunnel, it was stated that the government officials would be determined by popular vote, and a vote was requested from its official address until December 10. However, on December 11, the authorities did not disclose the result of the voting on the site and did not share the issue on the grounds that the issue was distorted. The tunnel was opened on December 20, under the name of "Eurasia Tunnel", without changing the name.
Eurasia Tunnel Project
The Eurasia Tunnel Project (Istanbul Strait Road Tube Crossing Project) connects Asian and European sides with a road tunnel passing under the sea floor. The Avrasya Tunnel, which serves in Kazlıçeşme-Göztepe line where there is a heavy traffic in Istanbul, covers a total of 14,6 kilometers.
The 5,4 kilometer section of the project consists of a two-storey tunnel constructed with a special technology under the sea floor and connection tunnels constructed with other methods, while road expansion and improvement works were carried out on a total of 9,2 kilometers in Europe and Asia. The approach roads between Sarayburnu-Kazlıçeşme and Harem-Göztepe were expanded and intersections, car underpasses and pedestrian overpasses were built.
Tunnel passage and road improvement-expansion work, a holistic structure that relieves vehicle traffic. While the journey time in Istanbul is very heavy, the journey time is significantly reduced, and it is possible to experience the privilege of a safe and comfortable journey. It also contributes to the reduction of environmental and noise pollution.
Tunnel excavation and 'Lightning Bayezid' called tunneling machine (TBM); 33,3 with 2 kW / m1 cutting head power. 12 with 2 bar design pressure. and 147,3 with cutting head area 2 m6. ranks.
The 'North Anatolian Fault', which has a high seismic activity, passes near the 17 km of the Eurasia Tunnel. The seismic joints (seismic joints / gaskets), which are designed to reduce the stress and displacement of seismic activities to an acceptable level, have been carefully determined in the tunnel. The displacement limits were ± 50 mm for shear and ± 75 mm for elongation / shortening. Seismic rings were tested in laboratories and produced after their conformity and success were proven. Given the geometric dimensions and the level of seismic activity to be exposed to the bracelets, the CPC was the 'first' practice with these features in the tunneling industry.
In the design of earthquake behavior, the moment magnitude Mw = 7,25 has been accepted; 500 's "service conditions" against the earthquake that can be seen once a year and 2.500 against the earthquake that can be seen once a year "security conditions" could act without distortion. In the design phase, the seismic bracelet positions were successfully determined and the 'cutting head' torque was continuously measured during the construction of the tunnel.
440 cutting disc, 85 chisel and 475 brush were changed during excavation of tunnel. During the excavation, due to the ever-changing geological conditions, 4 had to undergo hyperbaric maintenance and repair operations by 'specially trained divers' and all were completed successfully. One of these operations, which caused total 47 day time loss, came about to the deepest point of the Tunnel. As a result of the successful completion of this repair and maintenance operation which has to be done in an untested pressure environment like the 10,8 bar, a 'first' was carried out in the world and the excavation was continued.
The Ministry of Transport, Maritime Affairs and Communications and the General Directorate of Infrastructure Investments (AYGM), Eurasia Tunnel Management Construction and Investment Inc., which was established with the partnership of Yapı Merkezi and SK E&C companies to realize the design, construction and operation of the Eurasia Tunnel Project ATAŞ). The Eurasia Tunnel will be transferred to the public with the completion of the operation period.
1 with the build-operate-transfer model 245 was launched in December 22 with an investment of billion 2016 million dollars.
According to the information notes of the General Directorate of Infrastructure Investments
- Investment period: 55 months (4 years 7 months)
- Operation period: 24 years 5 months
- Commissioning according to contract: August 2017
- Destination: December 2016
- Traffic guarantee: 25 million vehicles a year (68.500 vehicles per day)
- Public share in case of over-warranty vehicles: 30%
2017 million vehicles passed through the tunnel in 15.6,  and 2018 million vehicles in 17,5. The day of the highest pass took place on Mother's Day, May 13, 2018, with 65 vehicles. 
On March 1, 2011, the Istanbul Branch of the Chamber of Urban Planners filed a lawsuit against the decision of the Conservation Board, claiming that the project caused damage to the public, that there was no zoning plan and that the historical buildings to be destroyed were not identified.
- Engineering News Record (ENR) Magazine, En Best Tunnel Project Worldwide ”, October 2016
- ITA (International Tunnel Association) International Tunneling Awards, 'Project of the Year' Award, November 2015
- European Bank for Reconstruction and Development, Best Environmental and Social Practice Award, May 2015
- Thomson Reuters Project Finance International (PFI), Best Infrastructure Project Financing Agreement, 2012
- Euromoney Project Finance, Europe's Best Project Finance Agreement, 2012
- Emea Finance, Best Public-Private Partnership, 2012
- Infrastructure Journal, Most Innovative Transportation Project, 2012