The tunnel is being built to bypass the steep and twisty route at Sabuncubeli Pass, reducing the grade of highway from 7–8% to 1.5%.

The new project featured the extension of the tunnel length from initially planned 2.8 km (1.7 mi) to 4,070 m (13,350 ft),[2][6][11] and a lesser road grade than of previously designed.

[3] A landslide, which occurred in the western tube on the northeast portal during the excavation works in 2013, caused the lengthening of the tunnel to now 6,480 m (21,260 ft),[9][10] and hence a delay in the construction's completion.

[4][12] The constructing company had the concession to operate the tunnel for a time span of 11 years 11 months and 11 days after its opening, and to collect the Turkish lira equivalent of US$2.50 as toll but it went bankrupt.

[14] Hasan Sözbilir, a professor at Dokuz Eylül University and member of the Izmir Branch of the Chamber of Engineering Geology, warned at a press conference in December 2012 that the Sabuncubeli Tunnel is situated entirely on one of the fault zones in the region.