Beneath the slab, 14 covered walkways—including two main routes (the Builders’ Walkway and the Sculptors’ Walkway)—have been brought up to regulatory standards. 

Objectives:

• Improving safety on the Builders’, Sculptors’, and Pyramids’ walkways (BSP)
• Incorporating non-motorized modes of transportation: pedestrians and cyclists (BSP)
• Redevelopment of the lanes to create bright, airy environments
• Improvement and optimization of logistics flows
• Enhancing cross-connections between the Sculpteurs and Bâtisseurs routes to ensure cohesion and permeability throughout the complex
• Modification of the road network
• Ensuring high-quality access points to the covered routes

The Sculpteurs Route is a 650-meter tunnel, while the Bâtisseurs Route measures 725 meters. These two main thoroughfares serve 25 office towers. Currently used primarily by vehicles, the Paris La Défense public authority is encouraging the towers to redesign their layouts and entry points to accommodate cyclists, providing services at the base of the towers such as secure parking, lockers, or even showers.

This project paves the way for renovating the underground passageways to make them more pleasant and bring them closer to the status previously enjoyed by above-ground areas. In other words, the underground passageways will become pleasant, safe, and well-lit spaces to traverse.

A total of 100 million euros has been allocated for the redevelopment of these streets. The project also includes plans to create delivery and waste collection zones, dedicated two-way bike lanes (currently under construction), and ceiling panels to enhance the aesthetic appeal.  The installation of skylights allows  for air circulation and the entry of natural light, creating a light path whose color-coded system helps users orient themselves beneath the slab.

From a broader perspective, this project improves user safety and safeguards operations in the event of a fire in the tunnels. Furthermore, these regulatory measures enable urban development by introducing pedestrianization and non-motorized transportation (bicycles) into the covered passageways (in progress).

To support the use of the pathways by non-motorized modes of transportation, four openings (also known as vents) in the slab help facilitate natural ventilation, thereby improving the structure’s safety in the event of a fire. These openings, distributed along the Sculpteurs Pathway, complement the existing openings.