The Corridor Xa is one of the Pan-European corridors. It runs between Graz, Austria and Zagreb, Croatia through three countries: Croatia, Slovenia and Austria. The road route of Corridor Xa is concurrent with E59 throughout its entire length.
The corridor starts at the A9 highway in Graz, Austria. It follows the highway for 38 km (24 mi) to the border with Slovenia.
In Slovenia the corridor continues along the A1 highway to the city of Maribor. There it switches to the A4 highway until Ptuj, continuing (while A4 construction is in progress) on the G9 main road for a few dozen kilometers to the Croatian border.
In Croatia the corridor follows the A2 toll highway for 64 km (40 mi) from Macelj to Zagreb outskirts. The highway has four to six lanes throughout its entire length. Upon approaching Zaprešić interchange in suburban Zagreb, small backups on the mainline toll plaza are encountered at all times of day. The last part of the Corridor between Zaprešić and Lučko interchanges is part of the Zagreb bypass. Congestion can be bad at rush hour near interchanges, though.