Which equipment must be carried on a bus in unfavourable road and weather conditions?

You answered correctly. In Germany, when buses operate under unfavourable road or weather conditions, it is required to carry snow chains as well as tools like a spade and hoe to deal with snow or difficult terrain. Additionally, having a tow-rope or a tow-bar is mandatory so that the bus can be towed if it gets stuck. A portable cable winch is not a legal requirement for buses. For similar questions, remember that standard legally required emergency equipment for buses in challenging conditions includes snow chains, tools to help free the vehicle, and equipment for towing, but not specialized recovery devices like winches.