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On June 6, 2025, a key milestone was achieved with the completion of the final opening phase of the covered trench on the Rondeau interchange. This marks significant progress for mobility in the Grenoble metropolitan area, in a strategic zone between Grenoble and Échirolles.
Launched four years ago as a continuation of the A480 upgrade (now expanded to 2×3 lanes), this large-scale project aims to ease traffic congestion on the RN87 while promoting active mobility and preserving the urban environment.
Working alongside the DREAL Grand Est (project owner) and DIR Centre-Est (project manager), setec opency oversees the coordination of all project contracts. It’s a complex undertaking in a densely populated area, with several key challenges:
Maintaining daily traffic flow of 100,000 vehicles on the RN87
Ensuring the continuity of a cycle path for soft mobility
Working within an active industrial zone
To manage this complexity, the project was divided into six main work packages:
TOARCH Package: Earthworks, civil engineering structures, utilities, and roadworks
Footbridge Package: Construction of a new cycle bridge over the A480
Water Package: Development of a retention basin and pumping stations
Equipment Package: Installation of safety and operational equipment in the covered trench
Directional and Signage Package: Road safety barriers, horizontal and vertical signage
Surface Development Package: Redevelopment of roads and public spaces in Grenoble and Échirolles
End of 2025: Commissioning of the new cycling footbridge, a strong symbol of the commitment to soft mobility.
February 2026: Final completion of the redesigned interchange, fully adapted to meet today’s challenges in traffic flow, safety, and quality of life across the Grenoble region.