Rafael Jaén Sánchez. Master ICCP (UPM) Student

Often, when we think of major public works, the first things that come to mind are cranes, asphalt, and structures that dominate the landscape. However, the most human-centered engineering is precisely the kind that cannot be seen. When designing a road or a railway, the simplest and cheapest option is usually to build on the surface, but that “ease” comes with an invisible price that we all end up paying: the fragmentation of our daily lives. A concrete barrier in the middle of a neighborhood doesn’t just separate streets; it separates people, breaks local commerce, and steals our horizon.

The surface is where life happens: where children play, where we walk, and where our homes are built. When we allow infrastructure to occupy that space permanently, we are “mortgaging” the city’s future. A surface-level track is a dead space, a piece of land that can no longer be a park, a daycare, or a town square. Moving these works underground is, in reality, an act of generosity toward future generations. It is about returning the land to them so they can decide what they want to do with it, instead of leaving them with a concrete scar that forces them to live with their backs turned to the other half of their city.

Bad planning practices are often born from looking only at spreadsheets rather than maps. Choosing a surface alignment to save money today means condemning the environment to noise, pollution, and isolation tomorrow. On the contrary, good practice understands that infrastructure must serve the people, and not the other way around. Solutions compatible with healthy development are those that “stack” functions: fast transport and utilities below, and urban life above. It is the difference between a city that feels like a maze of walls and one that feels like an open, connected home.

Ultimately, the success of a territorial plan should not be measured by the kilometers of concrete built, but by the amount of space we manage to keep free for people. The underground offers us the opportunity to hide what is functional to protect what is vital. By choosing the subterranean path, we are not just optimizing available area; we are choosing a kinder, more united, and, above all, much more vibrant city