During spring and autumn it can sometimes be so cold that rain and melted snow freeze during the evening and night, resulting in so-called slippery spots. The risk of slippery spots forming is especially great in shady areas and on bridges and viaducts.
Frost slipperiness can also be formed on snow-free roads during spring and autumn when the air's moisture freezes on the road surface. Frost slipperiness is most common at dawn and early in the morning after a cold and clear night. Fog can also cause frost slipperiness.
Drive carefully and be prepared for slippery roads after sudden temperature fluctuations and after cold evenings and nights.