The new section of motorway is 4.85 km long and combined with the sections inaugurated in September 2011 brings the total of newly constructed motorway to 19 km. With this portion of the road now operational, the carriageway in the direction of Andalucia is complete and the trip through the pass now takes about 9 minutes less. The Ministry of Development has spent 245 million euros on this project.

The Minister of Development, Ana Pastor, presided over the inauguration and start-up of the new section of the A-4 Southern Motorway between Venta de Cárdenas (Ciudad Real) and Aldeaquemada (Jaén), part of the southbound section of the Madrid-Andalucía motorway built by FCC which passes through the Despeñaperros Nature Park. José Mayor, Chairman of FCC Construcción and Avelino Acero, Managing Director of FCC Construcción were both in attendance on behalf of FCC, among other company representatives.

With this road construction project, which cost 245 million euros, the capacity of this traditionally critical section of motorway has been improved, as have safety levels and environmental aspects, cutting at least 9 minutes off the travel time.

This new section, which is 4.85 m long, combined with another section inaugurated last year, will reduce the travel time through the new Despeñaperros pass compared to the old one.

Before undertaking the project to improve this road, the Ministry of Development reached agreements with all of the parties that would be affected by the work, primarily the Despeñaperros Nature Park where most of the construction would be taking place. As a result of this undertaking, the old winding road has been transformed into a modern motorway that combines modernity with environmental respect. With today's inauguration of the southbound lanes of the road between the Venta de Cárdenas and Aldeaquemada junctions, the new Despeñaperros Pass is complete.

The new motorway through the Despeñaperros Pass is a three-lane road in both directions. The infrastructure, which currently supports average daily traffic of about 24,000 vehicles, 30% of which is heavy vehicle traffic, is expected to be used by some 57,000 vehicles by the year 2030.

Technical characteristics

The new section of motorway starts at kilometric marker 244 on the current A-4, southbound, and runs along a 500 metre section where there are two viaducts measuring 80 and 100 metres long over the Despeñaperros River as well as the 145 meter Corzo tunnel, all of which were part of the northbound portion of the old A-4. This section has been set up to accommodate southbound traffic and the tunnel has been equipped with all of the elements necessary to comply with the minimum safety requirements for tunnels contained in RD 635/2006.

At the other end of the Corzo tunnel and now in the Community of Madrid, the road changes from 2 to 3 lanes and connects with the 450 metre long Corzo viaduct over the Despeñaperros River. Next is the Despeñaperros tunnel which is 1925 metres long and runs through the "Los Órganos" nature reserve of special environmental value.
Following this, the road runs through the 280 metre Cantera Tunnel, at the end of which it connects with the 430 metre long Despeñaperros viaduct which was built using a movable scaffolding system to position the arched segments of the platform. This viaduct runs over the Madrid-Sevilla railway, the old northbound section of the N-IV and the Despeñaperros River.

Finally, at the Aldeaquemada junction located near kilometric point 251 of the current A-4 southbound, the road connects to the A-4 motorway that was inaugurated last September.

The trunk section of the road comprises two carriageways with three lanes in each direction measuring 3.5 metres wide, 2.5 metre outer shoulders and 1.5 metre inner shoulders. Between Santa Elena and Aldeaquemada there is a 5-metre median between white lines and a variable median along the rest of the section due to the presence of the tunnels.

The work included laying underground electrical power lines for the tunnels from the Almuradiel substation to Venta de Cárdenas (15 km) and a tunnel control centre located in Santa Elena which contains all of the safety devices installed to supervise tunnel operations.

Environmental integration

Environmental measures included the restoration of the southbound carriageway between kilometric markers 252.3 and 256.7. This restoration consisted primarily of recovering the tributaries of the Arroya del Rey and restoring the topography that had existed prior to the work done in the year 1984. To do so, the current embankments were cleared and the clearings were filled in, leaving a 5-metre wide forest trail running through the centre of the filled in area. This will ultimately be replanted with the characteristic trees and shrubs of each one of the habitats being restored.

A series of measures was also implemented to reduce and correct the environmental impact of the work, which included: improving permeability for fauna by eliminating one of the existing carriageways and increasing passageways; cleaning and restoring river beds and banks; improving the habitat conditions of rabbits and lynx; recovery of the endemic centaurea citricolor; repopulation and selective pruning for fire prevention purposes; integration of the tunnel openings into the natural landscape; restoration of the landscape in all affected areas; protection against noise pollution and protection of archaeological heritage.

This project required an investment of approximately 8 million euros.