It connects the two largest cities in Portugal, Lisbon and Porto, also passing by some district capitals and industrial zones.

Being the most important connection between two major cities, it was designed to be parallel to other roads, like the EN1.

At 303 km long, the highway starts in Lisbon, in the interchange between the CRIL and the Vasco da Gama Bridge.

Castelo Branco / Tomar Ourém Figueira da Foz Fig.

da Foz / Cantanhede Viseu (toll) Gaia via N1 Gondomar / Braga Espinho / Canelas Espinho / Valadares Canidelo ** Exit only available on South-North side