South Carolina Driver's Permit Practice Exam

What freezes first when wet?

1. Sidewalks

2. Roads

3. Bridges

4. Pavements

The correct answer is: Bridges

Bridges freeze first when wet due to their unique construction and the exposure of surfaces to air on both sides, which allows for faster heat loss. Unlike roads and sidewalks that are typically supported by the ground, bridges are elevated and are subjected to cold temperatures from above and below. This can cause moisture on the bridge surface to freeze more quickly, creating a hazardous layer of ice. Roads and sidewalks, while they can also become icy, are insulated by the ground beneath them, which helps to retain some heat. Because bridges are often one of the first roadways to freeze during cold weather, it’s crucial for drivers to exercise extra caution when crossing them in conditions where temperatures drop and wetness is present. This phenomenon makes awareness of bridge conditions especially important for safety during winter driving.