Starting from Eleusis in the Athens metropolitan area, the Olympia Odos motorways follow the Gulf of Corinth to the Rio–Antirrio bridge and the city of Patras, and along the Ionian Sea coastline, in future down to Tsakona (near Meligalas) in the southwestern Peloponnese where it will intersect with the A7 motorway.
In return for the right to collect tolls, the consortium will invest a total of €2.8 billion for construction and modernization of the highway.
[2] The upgrade of the A8 (Elefsina–Corinth–Rio) and the southern section of the A5 (Rio–Pyrgos–Tsakona) by Olympia Odos S.A. has been described as "the largest and most challenging project currently undertaken in Greece, and one of the most complex ones in Europe.".
[2] Subsequently, 82 km (51 mi) preexisting dual carriageway of the Patras bypass and the National Road 8a section Elefsina–Corinth) were further upgraded to full motorway standards.
120 km (75 mi) of preexisting single carriageway in the Corinth – Patras section were doubled.