The purpose of the work is the realization of “subsection of Marão Tunnel” inserted in the A4 – Motorway of Marão. The layout of the sub-section begins at km 13 + 825, is developed to the east, in direction to Vila Real, up to KM19 + 650. In stroke they are encompassed, the tunnel, and the two small connecting sections immediately adjacent to the Art works: Viaduct V9 V10 to the West and the Viaduct Tunnel East.

The tunnel route is part of the Marão motorway, starting at km 13 + 825 Project Execution IP4 (A4) – Amarante / Vila Real, after the expansion joint Viaduct V9, developing to the KM19 + 650, on the border with Viaduct V10, which is referenced mileage to calculate the guideline of the South gallery, towards Amarante / Vila Real (West / East, w / e). The track is so 5825 m long.

Marão tunnel was designed to consist of two parallel tunnels, called North Tunnel (East / West, and / w) and South Tunnel (West / East, w / e), with approximately 5667 m each, making a total of 11,335 m of tunnel, crossing the Serra do Marão and develop into approximate direction west / east.

The Monitoring Team has 8 technicians, coordinated by Eng. Rui Borges.