San Sebastián Metro

Euskotren operates frequent commuter rail services in the city of San Sebastián and the surrounding Donostialdea area, in the Basque Country, Spain. The infrastructure is gradually being upgraded to rapid transit standards, in order to create the San Sebastián Metro (Metro de San Sebastián, Donostiako metroa). The line is commonly known as, due to the large number of tunnels present. As of 2021, the San Sebastián suburban rail services are branded as part of the Euskotren Trena network, with no separate identity.

History
The meter-gauge line opened on December 5, 1912 between San Sebastián with Irun. It was extended to Hendaye the following year. The network was subsequently owned by FEVE, the Spanish narrow-gauge railway company, until it was transferred to the Basque Government in the 1970s. In the early 1980s, it was integrated into EuskoTren, along with other narrow-gauge lines in the Basque Country.

Since the 2010s, the line has been gradually upgraded towards rapid transit standards. In 2012, together with the opening of a new tunnel between Loiola and Herrera, it was announced that the line would be renamed to Metro Donostialdea. This branding, however, has since been abandoned. In 2015, a branch was opened from Herrera to Altza. This branch will be part of the new alignment between Herrera and Galtzaraborda.

Future developments
A 4.2 km underground loop through the city centre was originally planned to open in 2022, but is now  scheduled for 2025 or early 2026. This new tunnel will have three stations: Benta Berri, Centro-La Concha and Easo; the last one of which will substitute the current Amara terminus. When the tunnel is completed, the need to reverse at Amara will disappear.

The works on the new Altza-Galtzaraborda stretch began in February 2022, with completion scheduled for 2027. This new alignment will simplify operations by absorbing the Altza branch into the main line. When completed, the line will be double-tracked between Errekalde and Galtzaraborda.

Operations
There are two numbered lines: E2 and E5. Line E5 runs from Amara to Altza every 15 minutes on weekdays, and every 30 minutes during most of the weekend. Line E2 has two services: one from Lasarte-Oria to Irun, and another one from Lasarte-Oria to Hendaia; each running every 30 minutes during weekdays. The Irun to Lasarte-Oria service is reduced on weekends to a twice-hourly service from Irun to Amara on Saturday afternoons. Additionally, trains running on the Bilbao-San Sebastián line call at all the stations between Errekalde and Amara.

Due to the existence of various overlapping services, headways vary depending on the time of the day and location. Since 2012, with the opening of the new Loiola-Herrera tunnel, there is a train every 7.5 minutes between Amara and Herrera. With the opening of the tunnel through the city center, it will be possible to offer regular headways in a longer stretch of the line.

Station list
The following table shows regular weekday service patterns. The first trains in the morning and the last in the evening make shorter trips.

Trains stop at stations marked with "●" and don't stop at those marked with"｜":

Rolling stock
The line shares rolling stock with the rest of the Euskotren Trena network. Currently, 900 series trains are used. In the past, 200, 300 and 3500 series trains were used.