What do you do when you see this traffic sign on an autobahn?

You are correct in choosing to increase your alertness and maintain a greater distance to the vehicle in front when seeing this sign. This triangular sign with cars in a row warns of a possible traffic jam ahead on the autobahn. By being more alert and increasing your following distance, you reduce the risk of sudden braking collisions.

Additionally, in case a traffic jam actually forms, you must brake carefully and switch on your hazard warning lights to alert vehicles behind you. This improves overall safety during the jam.

However, you should not move onto the hard shoulder and proceed in a traffic jam, as this is generally prohibited unless directed by authorities or emergency scenarios. The hard shoulder is reserved for emergencies, not for bypassing traffic jams.

Understanding this helps you react appropriately to traffic jam warnings: stay alert, keep distance, brake safely when needed, and use hazard lights—never use the hard shoulder to drive past the jam. This promotes safe and responsible driving on the autobahn.