What are Hazard Warning Lights (Feux de Détresse)?

Hazard warning lights, or 'feux de détresse' in French, are a vehicle's signaling system that activates all turn signal lights at once. Their primary purpose is to warn other drivers that your vehicle poses a temporary danger or obstruction on the road. They are a critical tool for enhancing road safety by making your vehicle more visible and alerting others to potential hazards ahead, even when the engine is off.

When to Use Hazard Warning Lights in France

According to the French Code de la route, hazard warning lights must be used exclusively in situations where your vehicle presents a danger to other road users. This includes specific scenarios:

• Breakdowns or Mechanical Issues: If your vehicle is immobilized on the carriageway, hard shoulder, or emergency lane due to a breakdown or mechanical failure, you must activate your hazard warning lights to signal your presence.
• Accident: In the event of an accident, whether your vehicle is directly involved or if you are the first to arrive at the scene and need to stop to assist, you should use hazard warning lights to alert approaching traffic.
• Temporary Obstruction: If you are forced to drive at a significantly reduced speed or temporarily stop in a dangerous location (e.g., briefly for loading/unloading in a place where your vehicle creates a hazard, not just an inconvenience). However, they are not to be used for regular parking, even if it's double parking. The law states that double parking is an inconvenience, not a danger requiring hazard lights.
• Slow-Moving Traffic: In an uninterrupted line of traffic moving very slowly or stopping, especially in poor visibility, it is common practice and sometimes recommended for the last vehicle in the queue to use hazard warning lights to alert following drivers. Modern vehicles often activate them automatically during sudden, heavy braking (Emergency Braking Assist systems).

Misuse and What Not to Do

It's equally important to understand when not to use hazard warning lights. Using them improperly can confuse other drivers and negate their safety purpose. For instance, using them to signal that you are simply stopped illegally (e.g., double parking in an urban area) is incorrect. This action obstructs traffic but does not constitute an immediate danger in the sense that hazard lights are intended to communicate. For simple stopping or parking, even if temporary, turn signals are used to indicate an intention to maneuver, not hazard lights.

Hazard Warning Lights and the Driving Theory Exam (ETG)

Questions on the French driving theory exam (ETG) frequently test your knowledge of when to correctly use hazard warning lights. You will need to identify appropriate scenarios for their activation and distinguish them from situations where normal turn signals or no special lighting is required. Understanding the nuance between a 'danger' and a mere 'inconvenience' is key to answering these questions correctly. Incorrect answers can lead to a failed exam. Always remember their purpose is to indicate an unforeseen and immediate hazard.

Importance for Road Safety

Proper use of hazard warning lights significantly contributes to road safety. They provide an early warning to other motorists, giving them more time to react, slow down, or change lanes, thereby reducing the risk of rear-end collisions or other accidents, especially in poor visibility or at night. They are an active signal that demands attention, unlike passive reflective devices such as warning triangles (though these should also be used in conjunction with hazard lights during breakdowns outside urban areas).