A 14 km path of light

The TZ4 (TZen4), a new Bus Rapid Transit line, stretches over 14 kilometers, connecting Viry-Châtillon, Grigny, Ris-Orangis, Courcouronnes and Évry-Courcouronnes through evolving urban landscapes. Designed to enhance mobility while ensuring lasting comfort for users, the line is supported by a carefully considered lighting strategy, where each element helps structure space and reinforce the line’s identity.
Here, light goes beyond its purely functional role. It unifies urban sequences, guides movement and reveals the surrounding environment, creating a clear and continuous visual experience. The project embraces a deliberate simplification of lighting furniture, favoring restrained, coherent solutions that integrate seamlessly into the existing urban fabric.
Resource optimization was a key driver of the design process. A detailed analysis of the existing lighting infrastructure enabled the reuse of more than one third of the installed equipment, significantly reducing environmental impact and generating savings of over €200,000, nearly one sixth of the total lighting budget.
Each area benefits from a tailored lighting approach focused on visual comfort and use: 3000 K lighting for roadways to ensure clarity and nighttime safety, and warmer 2700 K lighting for sidewalks and station platforms, creating a more welcoming atmosphere. Nighttime dimming further optimizes energy consumption while preserving perception and security.
A defining element of the TZ4’s luminous identity, the ARCHITEKTA column acts as a subtle yet unmistakable landmark along the route. Installed on the platforms of all 30 stations, it marks each stop with elegance and precision. Its slender silhouette, enhanced by a luminous ring in the colors of Île-de-France Mobilités, makes it both a functional signal and a sensitive spatial marker.
Through the TZ4, light becomes a tool for continuity, comfort and identity. A contemporary vision of urban mobility, where each point of light contributes to the legibility of the territory and to a fluid, harmonious nighttime experience.