Adif has begun track assembly for the C‑4b extension between Colmenar Viejo and Soto del Real. Work is starting in the vicinity of Soto del Real station and will progress gradually towards Colmenar Viejo.
This phase involves laying sleepers, rail and ballast on a formation that is already virtually complete. Although originally designed for double track, the platform has had to be widened to 13 metres to meet current standards. The section will, however, be opened as single track. In parallel, structures and transverse drainage are being adapted, along with wildlife crossings.
Complementary works are continuing alongside: longitudinal drainage, ditches and ducting for future installations, as well as progress on control, command and signalling systems, communications and power supply.
The C‑4b extension, a cornerstone of the Madrid Cercanías Plan, also includes electrification of the line and the transformation of the historic Soto del Real building into the new Soto Sur station. These works cover restoration of the listed building, construction of a car park and catering facilities, plus renewal of station access.
Although the line was originally planned to reach the proposed Soto Norte station, it will now terminate at the site known as Soto del Real–Manzanares, some 3 km from the town border and 4 km from the town centre.