The project, known as Paseo Verde del Sureste, involves putting part of the A5 underground to reduce the impact of surface traffic and reclaim urban space.
On the approximately 1.5km section from Batán to the area around the Casa de Campo amusement park, 1.3km of the south tunnel has been excavated, while 730m of the north tunnel drive has been completed.
The project also includes pile installation and construction of the tunnel roof slab, which has already been completed.
In March, FCC Construcción announced it had connected two tunnel galleries on Lot 1.
