The process of constructing the surface subway began in 1991. The first line was inaugurated on December the 7th, 2002.
Built on the concept of light rail, for most of its journey it runs on the surface. This feature leads to a very significant impact, not only by the change that its construction generated in the design of public spaces and public infrastructures, but also by the transformation it originated in the city's image.
The subway line is currently 70 km and has 80 stations, fourteen of which are underground.
The overall coordination of the project was done by the architect Eduardo Souto Moura with the participation of other architects who were allocated different projects sections: José Bernardo Távora, Rogério Cavaca, João Álvaro Rocha and José Gigante.