Redevelopment of Gate B
CERN will redevelop Gate B at the Meyrin site between August 2026 and March 2027.
The project forms part of CERN’s ongoing efforts to strengthen site security in line with international requirements. Following the introduction of new minimum operational security standards for international organisations by the United Nations Department of Safety and Security (UNDSS), CERN launched a programme to enhance the security of its perimeter and site entrances.
The redevelopment of Gate B will also bring operational benefits. The project will increase the capacity of the entrance, improve vehicle holding and turnaround areas, facilitate the future implementation of the Bus Rapid Transit (BHNS) project along Route de Meyrin and support the integration of active mobility infrastructure. In addition, CERN will use the opportunity of the works to connect the ME9 electrical substation to the SIG 18 kV network.
Key phases
3 August – 30 August 2026
31 August – 4 October 2026
5 October – 8 November 2026
11 November 2026 – 7 February 2027
Dates may be subject to minor adjustments.
Alternative site access arrangements
During the closure periods (31 August 2026 – 7 February 2027), the following arrangement will be in place:
| Gate | Opening hours | Access |
|---|---|---|
| Gate A | 24/7 | Light vehicles, pedestrians, and cyclists. A CERN guard will be available to assist visitors. |
| Gate C | Monday to Friday, 06.00-20.00 | Light vehicles, pedestrians, and cyclists. |
| Gate E | Monday to Friday, 07.00-20.00 | Two-way access for personnel and contractors. |
| Gate D | 07.00-19.00 | Buses and oversized vehicles. Access outside these hours is available on request to the CERN Access Control Centre (CSA): +41 22 767 6666. |
| Inter-site tunnel | Unchanged | Access restricted to authorised users. |
During the partial closure at Phase 4 (11 November 2026 – 7 February 2027), Gate B will remain open for exits only for vehicles, pedestrians and cyclists.
Traffic, mobility and building access changes
From 31 August 2026, the current bus stop at B300 will be replaced by the stop at B39. The bicycle station currently located near B120 will be relocated to B124 and merged with the existing station there. Further information will be communicated in due course.
During Phase 2, the junction between Route Pauli and Route Einstein will be closed. Those travelling between Route Einstein and Route de Meyrin should follow the diversion route via Route Democrite and Route Rutherford. Temporary traffic signage will be installed to guide road users.
Access to B55 from the Gate B side will be closed throughout the works. B55 will remain accessible via B56.
Phase 1 (3 August – 30 August 2026)
Preparatory works. No impact on access.
Phase 2 (31 August – 4 October 2026)
Full closure of Gate B and the Route Einstein/Route Pauli junction
- Intersection Route Einstein/Route Pauli closed: Follow diversion route via Route Democrite and Route Rutherford
- Bike station moved to B124
- Bus stop B300 replaced by B39
Phase 3 (5 October – 8 November 2026)
Full closure of Gate B
Phase 4 (11 November – 7 February 2027)
Gate B for exit only (vehicles, pedestrians, cyclists)
Additional closures (Weekends: 12-14 February, 5-7 March 2027)
Full closure of Gate B and the Route Einstein/Route Pauli junction for finalisation works during two weekends (Friday evening to Sunday)
