When you are driving in heavy snow in the dark it is most appropriate to use fog lights or, if your car does not have fog lights, dipped headlights.

In the event of fog, heavy rain or snowfall it is usually both more efficient and safer to use fog lights or dipped headlights than full beam headlights. This is because the light is so powerful and is directed at such an angle that it is reflected back at you from water particles.

Dipped headlights and fog lights must never be combined.

Read more about correct lighting