The movement of goods between Ariz and Lasarte was very high and it was expected to be increased in the near future due to the lack of double line sections that would allow crossing units.

Thus, the general objective of the project was to split the line Donostia-Hendaia into Renteria and Portomoko and two new stations were constructed: La Fanderia and Oiartzun.

Activities carried out included:

Alignment alternatives study based on Preliminary Design;
Conceptual Design of the best solution based on technical, economical and environmental criteria;
Detailed design of the infrastructure, cable crossings, post anchors in viaducts, etc.