Visibility is considerably reduced. When are you allowed to switch on fog headlamps?

The combination of options is correct. According to German traffic regulations, fog headlamps can be used in specific situations where visibility is significantly reduced. This includes conditions such as heavy rain, falling snow, and fog.

Using fog headlamps helps improve visibility for both the driver and other road users, as they provide a wider and lower beam of light that reduces glare. It's essential to use these lamps appropriately to enhance safety on the road. Always remember that using fog lights is not allowed in clear conditions, as it can dazzle other drivers. Understanding when to use fog headlamps is crucial for safe driving practices.