The Works have consisted in, on one hand, the expansion of the inventory of bridges in Vizcaya, so as to incorporate those of new construction since the previous revision. The said inventory has gathered together the most representative data for each structure, such us; the typology, the materials employed and its geometry. Likewise, these structures have been subject to an initial main inspection, consisting in a visual inspection of damages, their diagnosis, and the analysis of future deterioration associated to the observed damages.

On the other hand, a revision has been carried out of the existing inventory and the corresponding detailed structural inspections, which were fulfilled in the previous inspection campaign in 2003, which have shown a greater degree of deterioration. In said inspections, apart from observing the damages reflected in said campaign, the evolution of reflected deteriorations, the appearance of new damages and the fulfillment of repairs have also been observed.

The field Works have employed the use of auxiliary units to fulfill the inspection, such as: aerial platforms, mobile cranes and the corresponding services to detour and cut off the traffic for is subsequent use.