The tunnel would be part of Struma motorway (A3), that runs between Sofia and the border crossing to Greece, at the village of Kulata.

The main reason to build a motorway tunnel of such length was to protect the environment in the Kresna Gorge.

[1] The construction was expected to begin in 2016,[2] using the New Austrian Tunnelling method due to the diverse geology in the Kresna gorge, which makes the usage of TBM inapplicable.

[3] The construction costs along with the access roads were estimated at 1.1 billion levs (~560 million euro).

[4] As of 2015, plans were abandoned and an alternative route east of the gorge is being considered, which will involve a series of shorter tunnels and viaducts.