It is situated between Vezirhan and Bilecik bypassing the Gülümbe Pass with hairpin turns.

The 2,465 and 2,474 m (8,087 and 8,117 ft)-long twin-tube tunnel carries two lanes of traffic in each direction.

The highway Mekece-Bilecik-Bozüyük on the north-south directed D.650 at a distance of 86 km (53 mi) is a heavy traffic route for transport of industrial and agricultural products connecting the regions Marmara, Aegiean, Central Anatoli and Mediterranean.

[1] In 2000, a financial agreement was signed between the Turkish and Japanese governments to build a divided highway with two tunnels at the steep pass.

Construction works on the highway began in 2003, and in 2010 the route was put into service.