In cold weather, which surface freezes before roads?

In cold weather, which surface freezes before roads?

• A. Bridges
• B. Roads
• C. Sidewalks
• D. Tires

Answer: (A)

In cold weather, surfaces that lose heat fastest will freeze first. Bridges do this because they’re exposed to cold air on both the top and the bottom, and they don’t have earth beneath to hold heat. The ground under roads stores heat and can be warmed by sun, helping the road surface stay above freezing longer. Under a bridge, wind can rush underneath and carry heat away, and the surrounding materials (metal and concrete) shed heat quickly. So bridges reach freezing temperatures before roads, making them prone to icing earlier in a cold spell.

In cold weather, surfaces that lose heat fastest will freeze first. Bridges do this because they’re exposed to cold air on both the top and the bottom, and they don’t have earth beneath to hold heat. The ground under roads stores heat and can be warmed by sun, helping the road surface stay above freezing longer. Under a bridge, wind can rush underneath and carry heat away, and the surrounding materials (metal and concrete) shed heat quickly. So bridges reach freezing temperatures before roads, making them prone to icing earlier in a cold spell.