What is the right course of action in this situation?

In this situation, the correct action is to continue driving as before, following the guidance of the warning signs and traffic management (cones and signs showing to pass on the left). You should keep a safe speed, stay alert, and maintain your lane through the narrowed section. Braking hard immediately is not necessary unless there is a sudden danger, and there is no reason to take a photograph of the scene unless you are involved in the incident. German traffic rules require you to adjust your driving calmly and safely according to the traffic situation and road signs, without causing unnecessary disruption or danger to others. In construction or incident zones, always follow temporary signs and road markings, and stay aware of your surroundings.