Protecting the accident scene
Knowing how to secure an accident scene to prevent a secondary accident: marking, vest, triangle and the right reflexes.
Updated 13 June 2026
The golden rule: P.A.S.
Faced with a road accident, three letters summarise the course of action: Protect, Alert, Assist. This P.A.S. sequence must be followed in this order. Protection comes first because it is essential to prevent a secondary accident before any other action.
P.A.S. = Protect – Alert – Assist. Always in this order. Protection comes before everything else.
Should you stop?
If the emergency services are already on site and the area is organised, it is better not to stop so as not to hinder their intervention. However, if the accident has just occurred and no one is yet intervening, you must stop. Failing to do so when you are involved constitutes hit and run. Failing to assist when you are able to do so constitutes failure to assist a person in danger.
Hit and run concerns only the driver involved in the accident. Failure to assist a person in danger concerns everyone: the driver involved, a passenger or a mere witness.
Securing the scene in 4 steps
As soon as you stop, park your vehicle so as not to create an additional obstacle and not to obstruct access for the emergency services. Then follow these steps in order.
Step one: immediately activate your hazard lights to alert other road users to the danger.
Step two: put on your high-visibility vest before leaving the vehicle. The vest must be kept within reach in the cabin, not in the boot.
Step three: place the warning triangle approximately 30 metres upstream of the accident. The aim is for it to be visible at least 100 metres away by approaching vehicles. If a bend or obstacle limits visibility, move the triangle further back.
The triangle must be visible at a minimum of 100 metres. If 30 metres is not sufficient because of a bend, place it further away.
Step four: if there is no risk of fire or explosion, turn off the ignition of the crashed vehicles and disconnect their batteries to reduce fire risks.
The special case of motorways
On motorways, it is forbidden for a pedestrian to walk on the carriageway. Therefore, never place your warning triangle on a motorway: it is far too dangerous. Only activate your hazard lights, put on your vest, get all passengers out from the right side and position yourself behind the safety barriers, as far as possible from the traffic.
On motorways: no triangle. Vest compulsory, exit from the passenger side, behind the safety barrier.
At night: making the accident visible
If the accident occurs at night, visibility is even more critical. Point the headlights of an undamaged vehicle perpendicular to the road to illuminate the scene without dazzling approaching drivers. If you have a torch, make large movements to alert road users.
If you pass an accident already being dealt with, you can flash your headlights at vehicles coming in the opposite direction to encourage them to slow down.
Avoiding a secondary accident
Several factors increase the risk of a secondary accident: a bend hiding the scene, the presence of a level crossing, vehicles carrying dangerous goods, or poor weather conditions (rain, fog, ice). In all these situations, exercise extra caution when marking the scene.
What to remember for the exam
Protection is always the first action. The vest is put on before leaving the vehicle. The triangle is placed 30 metres upstream, except on motorways where it is never placed. The 100-metre visibility rule takes precedence over the 30-metre distance rule.
Recap
- The P.A.S. rule (Protect – Alert – Assist) always applies in this order.
- The high-visibility vest is put on before leaving the vehicle.
- The warning triangle is placed 30 metres upstream, but it must be visible at a minimum of 100 metres.
- On motorways, never place the triangle: exit from the passenger side and position yourself behind the safety barrier.
- Do not stop if the emergency services are already in place so as not to hinder their intervention.
- At night, illuminate the scene by pointing headlights perpendicular to the road.
- Hit and run is punished by a 6-point deduction, 3 years' imprisonment and a 75,000-euro fine.
- Failure to assist a person in danger concerns everyone, not just drivers.
Test yourself
What is the first action to take when you arrive at the scene of an accident?
- ○Call the emergency services
- ○Assist the injured
- ✓Protect the scene
- ○Move the victims
Correct answer : Protect the scene
At what minimum distance must the warning triangle be visible to approaching road users?
- ✓100 metres
- ○50 metres
- ○30 metres
- ○200 metres
Correct answer : 100 metres
Sources: Sécurité routière (securite-routiere.gouv.fr) and service-public.fr.