The Toses tunnel is located between the municipality of the same name and the ski resort of La Molina, belonging to the municipality of Alp (Gerona). It is 3,904 m long and is located between km 29+745 and 33+649. It is a single track tunnel on ballast, electrified, with catenary. The repair areas total 947 metres, where the following actions have been carried out:
- Refurbishment of the lining
- Reconstruction of the support
- Longitudinal drainage
- Treatment of the backfill
