Improving the CERN Meyrin site: ongoing works and how to get around
Written by:
SCE Department
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As many members of the CERN community return from the summer break, a number of infrastructure projects are under way across the sites. While these works may temporarily affect traffic, parking and access, they form part of a broader effort to develop and improve CERN’s campuses.
The projects highlighted below are among the major infrastructure works currently taking place on the Meyrin site. They will strengthen security, modernise infrastructure, improve environmental resilience and contribute to the long-term development of CERN’s facilities.
Gate B redevelopment
One of the most visible projects currently under way is the redevelopment of Gate B. During the works, Gate Awill be open 24 hours a day, 7 days a week.
Gate B is being redeveloped as part of CERN’s programme to strengthen site security in line with international requirements and modernise access infrastructure. The redevelopment will increase entrance capacity, improve traffic flow, support the future mobility developments along Route de Meyrin and connect the ME9 electrical substation to the SIG 18-kV network.
Bulletin communication | Gate B redevelopment project page
Works on Route Einstein for the Building 133 and BR41 projects
Works taking place on Route Einstein are linked to the Building 133 and Building 41 Retention Basin (BR41) projects.
Building 133, the Recycling and Reuse Centre, is undergoing major renovation and modernisation to create a centralised platform for waste management, sorting, recovery and reuse. The project includes infrastructure upgrades, improved environmental compliance, enhanced stormwater management and new facilities for the collection and handling of reusable items and chemical waste.
The BR41 project will convert a former drinking-water tank into a stormwater retention basin. The works include the diversion of underground utilities and modifications to the stormwater drainage network serving the surrounding catchment areas. These changes will ensure regulatory compliance and strengthen the site’s resilience to heavy rainfall.
Bulletin communication to come | BR41 project page
Works on Route Bakker for the future Building 140
Preparatory works are under way on Route Bakker as part of the future Building 140 project. This initial phase includes the diversion of existing utility networks and the installation of the new networks required to serve the future building. Completing these activities in advance will facilitate the main construction works and ensure the smooth delivery of the project.
Building 140 will become a major facility at the heart of the Meyrin site, strengthening connections between key areas of the site.
Route Democrite and the IBDRS project
The ISOLDE facility, built in the early 1990s, produces radioisotopes for research in fundamental and applied physics, particularly in nuclear medicine for innovative cancer treatments. The Isolde Beam Dump Replacement and Sustainability (IBDRS) project will modernise the ageing infrastructure. As part of the project, Route Democrite will be temporarily closed during beam-dump dismantling operations.
Renovation of Buildings 376, 377 and 378
Buildings 376, 377 and 378 are being renovated as part of the SITE-CONS consolidation programme. The works will improve the safety, energy performance and appearance of the complex while maintaining technical activities. During Phase 1 (September to December 2026), a significant proportion of the parking spaces in the Érables car park will be occupied by the works. During Phase 2 (January to May 2027), the parking impact will be reduced, but Route Fermi will be closed.
Thank you for your patience
The map below provides an overview of the main worksites and traffic impact to help you plan your journeys around the Meyrin site between 31 August and 16 September 2026. Schedules may evolve and are subject to operational, technical and weather-related constraints. Further updates will be provided as the works progress.
Download the CERN Campus App and enable notifications to receive the latest campus notices and traffic updates.
