| Barcelona Metro line 4 | |
| Type: | Rapid transit |
| Locale: | Barcelona |
| Owners: | TMB |
| Operator: | TMB |
| Start: | Trinitat Nova |
| Stops: | 22 |
| End: | La Pau |
| Distance: | 16.71NaN1 |
| Journeytime: | 27 minutes |
| Stock: | 2100 and 9000 series Trinitat Nova, Vernedai depots |
| El: | 1,200 V DC rigid overhead wire |
| Map State: | uncollapsed |
Line 4, also known as Trinitat Nova – La Pau, usually called "línia groga" (yellow line), is a line in the Barcelona Metro network operated by TMB, and part of the ATM fare-integrated transport network. It serves the northern districts of the city, and it is being extended to the new major metro and rail stations Estació de la Sagrera and Sagrera-Meridiana.
Opened to the public in 1973, it serves the northern half of Barcelona using part of the infrastructure of Barcelona's first metro line the Gran Metro de Barcelona, covering a wide C-shaped area stretching from La Pau (in la Verneda) to Trinitat Nova, where it is linked with the recent L11. The that make up the whole line are underground.
Although in 1966 it was planned for line 4 to be a loop line connecting Trinitat Nova and La Pau stations with three intermediate stations, in 1974 the plan was subsequently changed such that it became a C-shaped line of today, with provisions for two extensions northeast of Trinitat Nova (to link it with line 3 at the border of Barcelona and Santa Coloma de Gramenet) and La Pau stations (intended to penetrate inside Santa Coloma de Gramenet) that have never been realised.
| District | Station | Opened | Connections |
|---|---|---|---|
| Nou Barris | Trinitat Nova | 1999 | Barcelona Metro |
| Via Júlia | 1982 | ||
| Llucmajor | 1982 | ||
| Horta-Guinardó | Maragall | 1982 | Barcelona Metro: L5 |
| Guinardó Hospital de Sant Pau | 1974 | ||
| Alfons X | 1974 | ||
| Gràcia | Joanic | 1973 | |
| Eixample | Verdaguer | 1970 | Barcelona Metro: L5 |
| Girona | 1973 | ||
| 1973 | Renfe Media Distancia R11, R13, R14, R15, R16 | ||
| Urquinaona | 1926 | Barcelona Metro: L1 | |
| Ciutat Vella | Jaume I | 1926 | |
| Barceloneta | 1976 | Renfe Operadora Euromed, Talgo (at) | |
| Ciutadella Vila Olímpica | 1977 | Trambesòs T4 | |
| Sant Martí | Bogatell | 1977 | |
| Llacuna | 1977 | ||
| Poblenou | 1977 | ||
| Selva de Mar | 1977 | Trambesòs: T4 | |
| El Maresme Fòrum | 2003 | Trambesòs: T4 | |
| Besòs Mar | 1982 | ||
| Besòs | 1982 | Trambesòs: T5 | |
| La Pau | 1982 | Barcelona Metro: L2 | |
| Santander | |||
| Sant Andreu | Sagrera-TAV | Renfe AVE (planned) | |
| Renfe Media Distancia: R12 FGC: R3, R4 Barcelona Metro: L1 L5, L9, L10 |