Today, the construction, operation and maintenance of the A1 motorway have been largely outsourced to private companies: Aftokinitodromos Aigaiou SA.

[citation needed] The part west of downtown Athens runs over the Cephisus river and Kifissou Avenue.

From north of the boundary of Voiotia - Phthiotis, up to near Velestino, the tollway runs close to the coast of the Aegean Sea.

In the early 1990s, work began on the entire length of the sections Athens - Thebes interchange, and Katerini - Klidi.

[7] As early as 1995, National Road 1 had highway specifications in the sections Athens - Yliki, Katerini - Klidi - Thessaloniki and Polykastro - Evzoni.

Construction costs are estimated to exceed €200 million, and the remainder of the axis from Polykastro to Evzoni, which has already been characterized a motorway will be upgraded with more modern features such as safety barriers, new signage and road improvements.

[16] In 2016, the northern interchange of Katerini was completed, after about 26 years of construction, due to expropriation and financing problems.

In November 2017, with the start of the tender for the privatization of Egnatia Odos and the announcement of its terms, it became known that the HRDH may include in the object of the Concession Agreement the upgrade of the section Halastra - Polykastro from expressway to motorway, which was confirmed in September 2018.