In this situation, are you obliged to ensure traffic safety at the scene of the accident?

Yes. According to Art. 44 para. 1 of the Road Traffic Act, every participant in an accident has a duty to secure the scene of the incident. On a high-speed road, like the one in the picture, this is particularly important to warn other drivers and avoid further collisions. You must immediately turn on your hazard warning lights and place a warning triangle at an appropriate distance.