Why should you have the traffic information switched on, when driving on the motorway?

You selected both correct answers. On German motorways, having traffic information switched on is important because it warns you about motorists driving the wrong way (so-called "Geisterfahrer") and gives reports about traffic jams. These warnings help you react promptly to dangerous situations and avoid unexpected congestion. However, it is not a legal requirement to have traffic information switched on; it is strongly recommended for your safety and up-to-date travel information. Knowing this helps you make informed and safe driving decisions, especially at high motorway speeds.