The diverse terrain crossed by the Egnatia Motorway together with the special environmental conditions encountered imposed the construction (provision for) 73 twin-bore road tunnels of an overall combined length of 100km (measured as single carriageway) measured at 50km of single carriageway. This means that 7% of the road axis length is carried through tunnels, the construction cost of which corresponds to X% of the total motorway construction cost.

The majority will be bored tunnels, while a few of them will be cut-and-cover ones.

A main consideration in tunnel design is the provision for cross passages between the tunnel bores for the case of a fire emergency. Special emphasis is placed on the installation of a high-standard monitoring and control systems, which will ensure the safe operation of tunnels.

Tunnels are also fitted throughout with a special ventilation system, built to cope both with ordinary operating conditions and with smoke extraction, e.g. in case of fire.  This system automatically (with the possibility of manual operation, if necessary) monitors the quality of the air in the tunnel and keeps it at the desired level.  Finally, control centres with high-technology telematic systems ensure the safe and economic operation not only of the tunnels but also of the entire Motorway.

The tunnel construction cost ranges between 8.000 € per running meter and 30.000 € per running meter.

The total Egnatia Motorway tunnel construction cost amounts to 1800 M€, VAT included.