As previously announced, the work to bury the A-5—which had kept the M-30 tunnel at Avenida de Portugal connecting to the Extremadura Expressway (outbound direction) closed since August 3—was completed on Monday, reopening the route to traffic that same morning.
“This work has marked the completion of one of the key milestones in the undergrounding of the A-5 and sets the stage for connecting the new tunnel to the M-30 network,” said the Madrid City Council.
Once this phase of the work is complete, the connection between the newly reopened tunnel and the entrance tunnel to Madrid—where similar work was carried out last summer—is practically finished, meaning the underground extension of the A-5 is now entering its final stretch.
As part of this process, a final traffic closure may be necessary before the end of the year: “In any case, we’ll carry it out at the end of the year, once traffic has also decreased substantially. Traffic also drops significantly in December , so we’ll take advantage of those weeks,” said Borja Carabante, the delegate for Urban Planning, Environment, and Mobility, as reported by El Economista.
September: A Key Month for the A-5 Underground Project and the Southwest Green Park

At this point, the civil engineering work for the underground section is expected to be completed next September. From that point on, work will begin to develop the space that will be freed up at ground level.
It is precisely in this area where, in addition to “removing one of Madrid’s major urban barriers from the surface and reclaiming more than 100,000 m² of space for citizens,” the so-called Southwest Green Corridor will be developed.
This is a 3.2-kilometer naturalized corridor project that will connect Madrid Río, Casa de Campo, and the Cuña Verde in Latina. With this project, the Madrid City Council aims to “stitch together” the neighborhoods located on both sides of the A-5, particularly in the districts of Latina and Moncloa-Aravaca.
The removal of this barrier will address a long-standing neighborhood issue and connect the neighborhoods of Lucero, Aluche, and Las Águilas with those of Campamento (Latina) and Casa de Campo (Moncloa-Aravaca).
The A-5 underground tunnel project involves an investment of more than 400 million euros and is one of the largest projects of its kind currently being carried out by the Madrid City Council.