When are you allowed to use hazard warning lights?
When stopped and temporarily obstructing traffic
When travelling during darkness without headlights
When parked on double yellow lines to visit a shop
When travelling slowly because you're lost
You mustn’t use hazard warning lights while moving, except to warn traffic behind when you slow suddenly on a motorway or unrestricted dual carriageway.
Never use hazard warning lights to excuse dangerous or illegal parking.
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