Maliakos-Kleidi motorway

The Maliakos-Kleidi project on which VINCI Construction Grands Projets was mandated consisted in rehabilitating and developing a motorway. This infrastructure is 245 kilometres long: 205 kilometres of motorway were to be rehabilitated and 40 kilometres of new motorway (the focal point of the project) were to be built. The new section to be created as part of a design-build mandate also includes construction of 3 dual motorway tunnels (11 kilometres long in total) to prevent the above-ground crossing of the Tempi Valley, which is a tourism destination, two dual flyovers, and embankments featuring small structures and hydraulic works.


In efforts to deal with ageing structures, the Greek minister for infrastructure and transport launched a vast motorway-rehabilitation project. Greece has three geographical focal points: Patras, Athens, and Thessaloniki. These three hubs are connected by motorway A1 which runs north-south. It connects the capital, Athens, with the regions of Thessaly and Macedonia. The Maliakos-Kleidi section is part of this motorway. This concession project for the 245-kilometre motorway was granted by the government of Greece.


In this project, the work package assigned to VINCI Construction Grands Projets includes the rehabilitation of a 30-kilometre motorway segment, including upgrading asphalt paving for 120,000 m2 of road surface, installing vertical and horizontal road signs and safety systems, planting 30,000 shrubs, restoring irrigation systems, and upgrading the lighting system.
The work package also encompasses specific new construction, including erecting 3,600 m2 of operational buildings in proximity to the Leptokaria toll station as well as toll barriers located at a nearby interchange. To the north, it includes the demolition and rebuilding – without disrupting traffic – of a 14,000-m2 bridge and creating 30,000 m2 of landscaping on a slab above a cut-and-cover trench located in the city of Katerini.
We also built a dual-tube motorway tunnel – known as Tunnel T1 – that features two traffic lanes 3.75 metres wide and an emergency lane 2.5 metres wide. Tunnel T1 consists of dual tubes linked by inter-tubes located at 300-metre intervals. The excavation section was quite large, covering over 110 m2 in the open section and up to 180 m2 in closed sections in more challenging geological terrain. Tunnel construction was divided into three major phases: excavation, concrete lining, and electrical and mechanical equipment. We used flexible primary supports and unreinforced concrete to create the lining segments.
As a result of the constraints we encountered, particularly regarding the presence of seismic faults in the valley, we employed a conventional permanent surfacing approach using reinforced concrete.

No excavation was subcontracted, both French and Greek managers oversaw production, and the workforce was 100% Greek. This organisational set-up enabled us to ensure high-quality work and meet stringent safety standards.



Major public works projects in Greece are vital for the country’s infrastructure’s competitiveness. Just as in the case of the Corinth-Patras (EKPPT) motorway, to which we contributed numerous works, this structure will drive local economic development. For Greece, these key European projects represented about 10,000 new direct and indirect jobs during the construction phase. Operating these structures adds another 1,000 jobs.
These major infrastructure investments in Greece are important to restoring the country’s economic performance and will create quick and safe motorway connections among its various regions.
Motorways are considered to be priority projects by the European Commission and the government of Greece since they are a key factor in creating employment and developing national and regional transport infrastructure.

Project participants

Ministry of Infrastructure, Transport & Networks

Project management
Aegan Motorway Concession Company S.A.

Key figures

Implementation dates
January 2008 to March 2016

Main tunnel
282,300 m3

69,640 m3

EKPPT motorway

Elefsina, Corinthe, Patras, Pyrgos, Tsakona