Which of the following roadways freeze first when wet?
Answers
Bridges and overpasses
Intersections
Tunnels
The Correct Answer and Explanation is :
Correct Answer: Bridges and overpasses
Explanation:
Bridges and overpasses freeze first when wet due to their unique structure and exposure to the elements. Unlike roads that are built at ground level, bridges and overpasses are elevated and exposed to air on both the top and bottom sides. This allows cold air to circulate underneath and above the bridge, making them more susceptible to rapid temperature changes. The air movement around these elevated structures facilitates quicker heat dissipation compared to solid roadways, which are insulated by the ground below.
In contrast, typical roadways and intersections are usually insulated by the earth beneath them, which helps maintain the road’s temperature. The ground acts as a thermal buffer, absorbing and retaining heat longer than the air, which slows down the freezing process. This is why, even in freezing temperatures, roadways and intersections can remain wet without immediately turning into ice.
Tunnels, on the other hand, are generally enclosed and protected from the direct effects of the outside temperature. Most tunnels have some level of heating or airflow to regulate temperature and prevent ice formation, though extreme conditions might still cause issues. The internal temperature inside a tunnel is more stable, influenced by the surrounding ground and the structure of the tunnel itself.
Bridges and overpasses have little to no thermal mass beneath them, which means they lose heat quickly, making them prone to freezing in conditions where the temperature drops below freezing. This is why these structures are often marked with warning signs that alert drivers to potential icy conditions, even when the roadways themselves are not visibly frozen. Drivers should exercise caution on bridges and overpasses in cold weather to avoid the risk of slipping and losing control of their vehicles.