When is a rear fog lamp allowed to be used?

The rules define the circumstances under which the driver of a vehicle may drive with the fog lights on.

– When is the rear fog lamp allowed to be used?

Article 30 of the SDA in paragraph 3 is set out as follows: “The driver of the vehicle can use the rear fog lights if the decrease in air transparency limits visibility at a distance of less than 50 m. In case of improvement in visibility, the driver must immediately turn off these lights.”

Apparently you can't. Rear fog lights are only really useful in conditions where visibility is drastically reduced. Their use in other circumstances is overly cautious, which puts other road users at risk.