What do you have to be aware of in this situation?

Your answers 1 and 2 are correct.

Answer 1 is correct because the warning sign with the “200 m” additional plate means the change will begin in 200 meters. Here it indicates that the left lane will become narrower ahead. The “200 m” does not mean the narrowing lasts 200 m; it tells you the distance until the hazard starts.

Answer 2 is correct because in such a narrowing you must consider your actual vehicle width in real driving, including anything that sticks out, especially the exterior mirrors. Even if the official vehicle width in the documents is smaller (often measured without mirrors), the mirrors are part of the real space your vehicle needs, so the risk of side contact increases when a lane narrows.

Rule of thumb for similar questions: an additional plate like “200 m” usually means “in 200 m,” while a plate like “on 200 m” or “for 200 m” would indicate the length of the hazard. When lanes narrow, slow down if needed, keep extra lateral clearance, and avoid driving side-by-side with large vehicles.