From November 21, with the launch of the 4.2 km underground tunnel, the 7.5-minute frequency will extend to the eleven stations of the Topo between Añorga and Pasaia, including the three new stations to be inaugurated that same day: Amara, Bentaberri, and Kontxa-Zentroa. The works have been carried out by Euskal Trenbide Sarea (ETS).
These metro-like frequencies – less than 10 minutes in railway terms – currently concentrated in eastern Donostialdea (between Amara and Pasaia), will now extend westward, doubling the train service. Once the underground tunnel is operational, Euskotren plans to run 276 daily services on the common Añorga-Pasaia section, with eleven stations, to complement the weekday service.
This service improvement is made possible by the removal of the dead-end siding at the Amara surface station; by building an underground tunnel, a continuous line can be created, offering a service without transfers between the western hubs of the territory (Bilbao, Zumaia, and Lasarte-Oria) and the eastern ones (Pasaia, Irun, and Hendaia).
The Minister of Sustainable Mobility, Susana Garcia Chueca, explained that "Euskal Trenbide Sarea is finalizing the three new stations, and Euskotren is completing the training of 197 drivers. Therefore, the countdown is on; the new Topo service, with its frequencies and new stations, responds to the current and future mobility needs of Donostia and its metropolitan area, and will be truly useful on a daily basis."
To organize different origins and destinations, Euskotren will change the names of its lines: E1 Matiko (Bilbao)/Zumaia – Pasaia, T0 Añorga – Pasaia, and T1 Lasarte Oria – Irun/Hendaia. Thanks to the connection of these three lines, a 7.5-minute frequency will be achieved on the common Añorga-Pasaia trunk from November 21.
The frequency of Euskotren services will not be limited to weekdays; the opening of the 4.2-kilometer underground tunnel from Donostia will bring significant improvements to the weekend service. The E1 Zumaia-Pasaia service will be doubled to run every 30 minutes year-round, and the T0 Añorga–Pasaia service will run every 7.5 minutes, except on Sunday mornings. On the T1 Lasarte Oria–Irun route, weekend frequency will increase from 30 to 15 minutes, and the T1 Lasarte Oria – Hendaia service will also be improved.
The increase in frequencies planned for the new Topo requires the incorporation of new rolling stock into Euskotren's current fleet, increasing from 62 to 67 units. This will happen when the five units manufactured by CAF from the 980 series begin their commercial service from November 21. These trains will have four cars, a capacity for 400 people, and a bathroom, along with all the technological advancements in accessibility and safety.
