Traffic on this strategic Barcelona route had been disrupted since last October. During this period, vehicles were diverted through the opposite tube, causing congestion in a tunnel that connects the city center with the Ronda de Dalt and the neighborhoods of Baix Guinardó and Carmel.

The works focused on fixing water leaks by repairing cracks. As an additional measure, a perimeter wall has been built on both sides of the tunnel to contain any future leaks. Furthermore, the tunnel entrances have been repainted and the interior steel cladding panels have been cleaned.

Regarding safety, the tunnel, which dates back to 1987 and is 1,300 meters long, now features new public address systems, radio communications, and fire detection systems. New surveillance cameras and emergency points have also been installed to improve safety.