With over 3,000 metres of track, and running at speeds of up to 310 km/h, the Spanish high-speed trains run on the longest network in Europe.

Creating new access to northern Spain, the AECOM team provided detailed design, quality reporting, onsite works including geotechnical studies, and geometrical and qualitative controls for a key 2km stretch.

Part of this section includes the Arroyo del Valle Viaduct, which consists of 27 caisson-type piers. It also features a 132-metre-high ogival arch, which, at the time of construction, was the third biggest arch in the world and the first of its kind in Spain.

The distance between the piers has required the use of 153-metre-long self-bearing formwork, the longest used in Spain. The viaduct has earned industry recognition for its technical design, integration with its surroundings and for the environmental measures applied.