The Corridor X is one of the pan-European corridors. It runs between Salzburg in Austria and Thessaloniki in Greece. The corridor passes through Austria, Slovenia, Croatia, Serbia, North Macedonia, and Greece. It has four branches: Xa, Xb, Xc, and Xd.
| Pan-European Corridor X | |
|---|---|
 Pan-European Corridor X highlighted in red | |
| Major junctions | |
| Start end | Salzburg (Austria) |
| End end | Thessaloniki (Greece) |
| Location | |
| Countries |  Austria Bulgaria Croatia Greece Hungary North Macedonia Serbia Slovenia |
| Highway system | |
The European Bank for Reconstruction and Development has given loans to support infrastructure improvements along Corridor X.[1]
Branches
X:Salzburg - Ljubljana - Zagreb - Belgrade - Niš - Skopje - Veles - Thessaloniki.
- Branch A: Graz - Maribor - Zagreb
- Branch B: Budapest - Novi Sad - Belgrade
- Branch C: Niš - Sofia - Plovdiv - Edirne - Istanbul via Corridor IV
- Branch D: Veles - Prilep - Bitola - Florina - Igoumenitsa (Via Egnatia)
Branch A (Corridor Xa)
Corridor Xa runs between Graz, Austria and Zagreb, Croatia through Croatia, Slovenia, and Austria.
Branch C (Corridor Xc)
Corridor Xc follows the route Niš - Sofia - Plovdiv - Edirne - Istanbul.
The road in Serbia from Niš to the Bulgarian border nearby Dimitrovgrad is recently upgraded to a motorway standard. The construction works in all sections are completed on November 9, 2019.[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. Trakia motorway (A1) runs from Sofia to Chirpan, where Maritsa motorway (A4), completed in October 2015,[4] branches off to Turkey.