The corridor passes through Austria, Slovenia, Croatia, Serbia, North Macedonia, and Greece.

The European Bank for Reconstruction and Development has given loans to support infrastructure improvements along Corridor X.

The road in Serbia from Niš to the Bulgarian border nearby Dimitrovgrad is recently upgraded to a motorway standard.

[2] In Bulgaria, I-8 road connect Sofia with the Serbian border, but Kalotina motorway is planned to supersede it.

Currently the transit traffic has to pass via the Sofia Ring Road, but a new bypass Northern Speed Tangent is under construction since 2015[3] and is expected to be completed in 2016.