You are driving outside built-up areas. Visibility is reduced to just about 50 m due to heavy rain. What applies in this situation?

In this situation where visibility is reduced to about 50 meters due to heavy rain, the selected combinations of overtaking prohibition and speed limit are both critical for safety.

1. Overtaking is prohibited for motor vehicles with a permissible total mass exceeding 7.5 tons: This rule is in place to prevent dangerous maneuvers in conditions of poor visibility. Large vehicles require a longer stopping distance and are less maneuverable, making overtaking particularly risky when you cannot see far ahead.

2. The maximum permissible speed is 50 km/h: In conditions like heavy rain with reduced visibility, this speed limit is enforced to help drivers maintain control of their vehicles and react appropriately to unforeseen obstacles or hazards on the road. It ensures that drivers can stop safely within the range of their visibility.

The third option regarding the rear fog lamp must be switched on is essential in reduced visibility conditions but is not one of the selected answers. Activating the rear fog lamp helps other drivers see your vehicle from a distance, which is crucial during heavy rain. It serves as a safety measure to prevent collisions.

Therefore, while the user's selections included two correct regulations, considering all relevant factors, including the need for fog lamps in such weather, is vital for comprehensive road safety awareness.