Tunnelling efforts in Turkey started with the construction of a subway tunnel in 1869. A French engineer named Eugene-Henri GAVANT developed a project for the construction of the tunnel, which would connect Karaköy (Galata) located on the northern coast of Golden Horn and Beyoğlu (Pera) districts. As part of the project, a funicular would be running through the tunnel. In 1875, the tunnel was officially opened. It was 550,80 m in length, 6,74 m in width and 4,90 m in height.

Due the political instability the world was going through, Turkey also failed to undertake large-scale tunnelling projects for highway routes until the foundation of the Republic of Turkey. Following the proclamation of the Republic of Turkey on October 29, 1923, priority had been given to railroad transportation and thus to the tunnels along these rail routes. Since highway transportation became more prominent in the 1950’s and subsequent years, the number of tunnel passes started to escalate accordingly.

Below are the examples of tunnelling initiatives by years:

• Constructed in 1954 with the traditional method, Hoynat Tunnel, 151 m long, is the oldest tunnel on the state highways which is located on the Perşembe – Fatsa route,
• In the 1960’s, the length of the road network in Turkey reached 60.000 km, out of which 1,2 km were composed of single-tube tunnels,
• In 1965, tunnelling projects were in full flow along the highway routes and 16 snow sheds were opened on the Tunceli –Pülümür road,
• Between 1970 and 1990, multi-lane express highways and motorways started to be constructed; thus, Dil İskelesi and Hereke Tunnels with double tubes, İzmit Cut-and-Cover Tunnel and the cut-and-cover tunnels under the Military Academy were built up in 1980, 1981 and 1988 respectively,
• Construction of Zigana Tunnel, which was the longest tunnel of that time with its 1.702 m length on Maçka – Torul highway, was completed in 1988,
• Kargı Tunnel was the first state highway tunnel constructed after 1990 by using the New Austrian Tunnelling Method (NATM) on Antalya-Dereboğazı road (opened to traffic in 1994),
• Nefise Akçelik Tunnel (which bears the name of our lady colleague civil engineer who spent strenuous efforts for the development and dissemination of tunnelling initiatives in Turkey) is a far-reaching, state highway tunnel with double tubes (3.805 m and 3.825 m) on Bolaman – Perşembe road, construction of which was completed in 2006,
• Ovit Tunnel on İkizdere – İspir state highway completed on 2018, which it is one of the long tunnels in the world. Çamlık and Riva Tunnels on the Northern Marmara motorway also fall under the category of long tunnels.

It can be concluded that with emerging technologies and improved construction methods, tunnels have become an indispensable part of Turkey by contributing to the geometric standards of highways.

Within the scope of the tunnel construction of General Directorate of Highways solely, 307 tunnels with the length of 465 km were built between 2003 and 2019. As of today 390 tunnels with the total length of 515 km serve on all our roads. In 2019, 29 tunnels with the length of 51,5 km were built.

Constructions are going on in 138 tunnels with the length of 530 km. Project studies continues in 250 tunnels with the length of 633 km. 250 meters of highway tunnel are built daily in our country. The project of 42 tunnels with the total length of 136,4 km is ready. Until 2023, 470 tunnels with a total length of 647 km are planned to serve in the highway network.

“ITA-AITES 2005 WORLD TUNNEL CONGRESS & 31^st ITA GENERAL ASSEMBLY” was successfully held on May 7-12, 2005 in İstanbul jointly by Turkish Road Association and International Tunnelling and Underground Space Association. During the event, Turkey and its neighboring countries had the chance to exchange knowledge and experience on the latest technologies in tunnelling.

For the last 15 years, Turkey has undertaken mega Highway, Railway and Subway projects, drawing attention from all over the world.

Under such projects, outstanding tunnels have been built up by using the latest design techniques and construction methods.

In all these projects and constructions, Turkey as a member country has benefited much from ITA – AITES experiences. In other words while determining the techniques, methodology and process management, ITA – AITES guidelines has been highly followed.

The Association has decided to become a candidate to host “ITA-AITES WORLD TUNNEL CONGRESS 2023 AND 49^th GENERAL ASSEMBLY” in Antalya with a view to discussing and sharing technical know-how and experiences gained by Turkey in tunnel designing and construction with international guests.

We hope that all ITA members will support our candidacy and look forward to meeting you in WTC 2023 to be held in Turkey once again as was in 2005.