Construction supervision and consultancy services of 4 lane (2x2) 43,26 km roads in earthquake zones of Sakarya - Kocaeli -
It is one of the most prestigious and unique transportation projects in Turkey’s history. It connects Asian side of Istanbul to European side under Bosporus strait dropping substantially traffic congestions of the suspension bridges crossing the strait. The project includes construction supervision of 15.02 km 2×2 and 2×3 roads, 3.34 km 2 stories undersea 2×2 TBM highway tunnel with diameter of 13.70 m, 5.40 km NATM connecting tunnel. Total length of tunnel is 8.74 km. Deepest elevation of the road tunnel is 106 m below sea level.