Involved in the expansion are the lines ISMAI - Muro - Trofa (metro to Muro and 'metrobus' to Paradela), Gondomar II (Dragão - Souto), ISMAI, Maia II (Roberto Frias - Parque Maia - Aeroporto) and São Mamede (IPO - Estádio do Mar).

The connection to Trofa includes the Ribela, Muro, Serra, Bougado, Pateiras, Trofa Sul and Paradela stations, for a total of 10.22 kilometres.

The Gondomar II line, entirely in metro, includes the São Roque, Cerco, Lagarteiro, Lagoa, Valbom, Hospital Fernando Pessoa, Oliveira Martins and Souto stations, with a length of 6.9 kilometres.

For the São Mamede line, also planned entirely in conventional metro, it includes the stations IPO II, ISCAP, São Mamede, Pedra Verde, Elaine Sanceau, Xanana Gusmão, São Gens, Senhora da Hora II and connection to the Estádio do Mar station, with 6.55 kilometres

Finally, the Maia II line proposes two solutions, both for conventional metro and 'metrobus': the first with 13.01 kilometres and 16 stations and the 'metrobus' 14.3 kilometres and 18 stations.

In either case, the stations are planned for Roberto Frias, Hospital São João II, Pedrouços, Giesta, São Gemil, Caverneira, Águas Santas, Milheirós, Gueifães, Maninhos, Catassol, Chantre, Parque Maia II, Espido, Ponte de Moreira, Verdes II and, if the 'metrobus' is chosen, Botica II and Aeroporto (BRT).

The contracting of initial studies for the new Porto Metro lines, presented in Gondomar, could cost up to 10 million euros, according to the Government decree, which comes into force today.