The opening of a new commuter rail line in the Basque Country represents an important step toward improving mobility in less-connected areas. This project is part of the autonomous region’s government’s initiatives following the takeover of the commuter rail networks from the Spanish government, thereby strengthening the region’s ability to directly manage rail transport development and respond more quickly to local needs.
A new commuter rail line will be launched in the Basque Country, connecting rural areas and small towns to the suburban rail network in the Bilbao area, the main nearby urban center. The announcement was made by the Basque Government’s Minister for Sustainable Mobility, Susana García Chueca, and the Secretary of State for Transport and Sustainable Mobility, José Antonio Santano.
The new C5 line, running between Karrantza and Aranguren, will connect the towns of Karrantza and Zalla in the Enkarterri region, located in the west of the province of Bizkaia.
The C5 line will operate five trains in each direction on weekdays and one train in each direction on weekends and holidays. The service will have Cercanías-style fares, which are more affordable than those for medium-distance trains, and will complement existing connections in the area: three medium-distance trains between Bilbao and Santander, as well as the “Carranzano,” a morning service between Karrantza and Bilbao, stopping at all stations on the C5 line.
The new services, supported by an annual investment of up to 900,000 EUR from the Basque Government, will increase the total number of train trips (Cercanías and Media Distancia) to 101 per week, representing an 85% increase over the current situation.
The project for the new commuter line “is a demand from the residents of Karrantza, who were calling for better public rail connectivity with the capital of Bizkaia [the capital of the province of Bizkaia is the city of Bilbao] and with other locations in Enkarterri [a subregion in western Bizkaia]. It is also one of the priorities established since the Basque Government assumed responsibility for managing suburban rail services, so that this area of the Basque Country can benefit from a better sustainable mobility service,” stated the Councilor for Sustainable Mobility.
The launch of rail services between Karrantza and Aranguren was made possible following the completion of electrification works carried out by Adif, a public company under the Spanish Ministry of Transport and Sustainable Mobility and the owner of the rail infrastructure on which both the new service and the entire Cercanías network in the Basque Country operate.
The electrification of the Aranguren–Karrantza section was part of the commitments made during the process of transferring powers and is included in a broader investment plan, to which Adif is contributing over 600 EUR million.
Following the completion of the works, the entire route between Bilbao and Karrantza is served by Renfe’s 436-series electric trains, the same ones used on the C4 line, the metric-gauge commuter service connecting Bilbao’s La Concordia station to Balmaseda/La Calzada.
Rail connectivity to the city of Bilbao
The new commuter rail line will be integrated into the Cercanías Bilbao suburban rail network, administered by the Basque Country authorities and operated by Renfe.
Trains will stop at six stations, serving a population of over 12,000 residents. At Aranguren Station (Zalla), passengers will be able to transfer to Line C4, which connects Balmaseda to Bilbao (La Concordia) and carries an average of approximately 94,000 passengers per month.
The Basque Country’s Takeover of the Rail Network
As of January 1, 2025, the Basque Government took over the administration of commuter rail services from the Spanish authorities, based on an agreement signed in November 2024, which also included collaboration with the operator Renfe. The agreement also included a commitment by the Spanish government, through Adif, to invest approximately 400 EUR million over the next ten years in the regional rail network.
In this context, several suburban networks were transferred, including the Bilbao Cercanías system—the main commuter rail network serving the metropolitan area of Bilbao and its surroundings.
The following lines were included in the agreement:
The Iberian gauge (1,668 mm) Cercanías network in Bilbao:
- C-1 Bilbao Abando – Barakaldo – Santurtzi;
- C-2 Bilbao Abando – Barakaldo – Muskiz; and
- C-3 Bilbao Abando – Orduña
The metric-gauge (1,000 mm) suburban network in Bilbao, represented by line C-4f Bilbao – Balmaseda;
The Iberian-gauge suburban network in San Sebastián (Donostia), consisting of line C-1 Irun – San Sebastián – Tolosa – Brínkola.
All these lines have a traffic volume of approximately 426 services per day and carry over 22 million passengers per year.
To increase the appeal of rail transport for commuters, Renfe has a rolling stock modernization program, through which 25 of the oldest trains, out of a total of 44, will be gradually replaced with new, more efficient, and higher-performance units by the end of 2027.
Taking over these services lays the groundwork for better adaptation of transportation to local needs and more coherent investment management. At the same time, it paves the way for the development of a modern commuter rail network capable of meeting growing demand. In this context, strengthening regional control and expanding these services are essential to making rail transport more attractive and reducing pressure on road transport.
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