Railway workers are public service employees, which means they can’t spontaneously declare a strike and walk out without warning. They must comply with a legal framework:

• One or more employee unions file a “Request for Immediate Negotiations” presenting one or more demands. The filing triggers a request for a meeting with senior management to discuss the union demands, which could potentially lead to a walkout.
• The meeting must be held within three days.
• After the meeting, senior management and the unions draft a joint document called a “statement of shared conclusions”, stating where they agree and disagree. This document is signed by the parties and distributed to all affected employees.
• If the parties can’t reach an agreement, the unions may file an advance notice of a strike five days before the strike is scheduled to begin.

There are two types of strike:

• an ordinary strike, or grève carrée, which lasts for a predefined period
• a grève reconductible, which can be renewed and for which there is no set end-date.

Certain positions must give notice if they intend to take part in the strike, and they must do so at least 48 hours beforehand. They file a personal statement of intent, or Déclaration Individuelle d’Intention (DII).

Employees considered essential to the execution of the transport plan are subject to this requirement:

• train drivers
• conductors
• switching station operators
• passenger information staff

Rail service employs a wide variety of people and equipment, and requires a large-scale organizational effort.

For a train to run, it needs:

• a driver
• a conductor (if necessary)

as well as:

• station staff
• switching station operators

Assigning and guiding rolling stock to the right location takes additional resources and organisation.

As a reminder, each driver is authorized only to operate certain types of rolling stock and work on certain specific lines, even in the event of labour unrest.

Locally elected officials at the city, department, and regional levels—the Autorités Organisatrices des Transports (AOT), or transport authorities—determine their constituents’ essential needs.

Those needs may include service to a hospital or secondary school, maintaining at least limited service on a line that serves an important industrial site or area where lots of people work, and so on. Authorities also consider the needs of people with mobility issues. These priorities determine the minimum level of service in the transport plan.

Transport authorities thus identify community needs and set minimum service requirements. SNCF drafts transport plans that meet those requirements, chooses the plan best suited to the expected level of disruption, and keeps passengers informed of service and itineraries.

• Two days out, we assess the personal statements of intent for each business: Transilien in the Paris region, TER regional trains, Intercités services, and TGV high-speed rail. With that information, we determine which level of service we can provide for each line and corridor.
• One day out, we craft a plan to consolidate services for each line, corridor, and operation to determine how traffic will be affected (normal, minor disruptions, general disruptions, or major disruptions).
• At 5:00 pm on the day before, we announce the details of our provisional transport plan via our passenger information outlets (SNCF Connect, the SNCF Voyageurs website, the Twitter accounts of the various lines, etc.) and on posters and flyers in stations. In stations passenger information volunteers—wearing red vests—also on hand to help travellers navigate their journey.

We face certain limitations and obligations that prevent us from issuing detailed passenger information sooner than the day before a strike:

• we need to know how many workers essential to network operation will be out on strike
• 48 hours before the strike, we need to estimate the number of striking employees for each business line and determine what level of service we can provide for each line and corridor
• the evening before the strike, we need to consolidate information on service levels for each corridor and line, and only then, at 5:00 pm, inform passengers about the provisional transport plan through our various communication channels.