Safety risks – Road Safety

Thousands of us use the CERN roads every day. With the variety of modes of transport, with motorbikes, (e-)bicyles and (e-)scooters joining cars and pedestrians on the network, we all have a role to play in keeping ourselves and each other safe.

When using roads, inside and outside CERN, common sense and common courtesy prevail. Look out for other road users, and for yourself! It’s not only Safety first. It’s Safety always.

In case of emergency or incident, call the CERN Fire & Rescue Service on +41 22 76 74444.



Speed limit

Regulatory framework

Everybody must respect the rules of the French and Swiss highway code on site, in the same way as outside CERN.

In particular, everyone using the road must moderate their speed, respect pedestrian and cycle paths and be mindful of other users at junctions and crossings.

The speed limit on the CERN sites is 50 km/h, and pedagogical speed radars are deployed in the most accident-prone areas of the domain.


In 2021 and 2022, 134 road safety incidents were reported on the CERN sites. Of these, 58 involved bicycles. This number is probably greater in reality as not all incidents are reported.

Type of Road Safety Incidents

The analysis of traffic incidents shows that the most common causes are lack of attention or lack of respect for other road users. Did you know that among the 58 cycling events, 18 incidents were linked to vehicles not giving way? Common sense and mutual respect, keeping in mind to exercise greater caution towards the most vulnerable users, are the cornerstones of road safety.

Reporting accidents
Reporting accidents are vital for the continued improvement of CERN's campus in terms of mobility and road safety.
If you are the victim or witness of an accident or near-miss, inside or outside the CERN site, report it promptly using the Incident Declaration Form (EDH).


The Site & Civil Engineering Department (SCE) is responsible for CERN's road infrastructure and mobility. Any issues with the roads or paved areas, such as repairs of potholes and pavements, and markings and signage, can be addressed to the Roads service.  

The Organization has a dedicated Mobility Working Group comprising representatives of all Departments, including the HSE Unit. The group regularly reviews road infrastructure matters and recommends measures to improve all aspects of mobility at CERN, including safety. These include how to improve traffic flow, develop cycle lanes and footpaths, and ensure an optimized infrastructure for the benefit of all users, whatever their mode of transport.

An increasing number of car park spaces are designed for reverse parking to avoid accidents and keep traffic flowing safely. Reversing out of a parking space can be dangerous, especially when it’s onto a busy road or into a cycle path.

In the event of a site evacuation, vehicles must exit the site rapidly. Reverse parking is therefore strongly recommended wherever possible for safety reasons. These sign below indicate where reverse parking is compulsory.

Reverse parking

Safety courses

CERN offers an e-learning module on Bike Safety, which is available on LMS. The course is mandatory for anyone wanting to rent a CERN-(e)bike.

Mandatory bike equipment

Mandatory bike equipment