English: Directly translated a "sign trailer" or "sign vehicle" is a trailer used for warning motorists about dangers ahead - e.g. road accidents or road work. It is equipped with cones to cordon off an area, shovels and brooms to clear the road.

This particular trailer is operated by Roskilde Fire Brigade and is primarily used for incidents on the motorway - e.g. accidents or lost goods. The text below the warnings sign reads "Accident".

Flashing lights are automatically lit when the sign is raised and can point to right, left or mark an "x". On top the two blue lights flash once and are followed by the arrow and the two bottom blue lights being lit. Pointing direction and raising/lowering is controlled from a remote control.