On several occasions this past week, many road surfaces around the region became quite icy despite excellent weather. The problem: frost.
This is a common problem during the winter, especially in times of mild weather. When the days are sunny and mild, road surfaces are usually dry. But on clear nights, the same road surfaces radiate heat out into space, causing them to cool down even more than the air. When the road surface temperature reaches the frost point, the road can become quite slippery. In some cases, road frost can be as slippery as a coating of freezing drizzle.
Bridge decks are often among the first places to become icy in such situations, but overall conditions can be quite variable, leading to the dreaded "scattered slippery spots" that can catch a driver by surprise.
Even in times of good weather, winter driving can be a challenge.
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