On freezing, wet days, which of the following roadways is most likely to hide spots of ice?
Answers
Roadways near the tops of hills
Roadways on bridges and overpasses
Roadways paved with asphalt
The Correct Answer and Explanation is :
The correct answer is: Roadways on bridges and overpasses.
Explanation:
On freezing, wet days, roadways on bridges and overpasses are the most likely to hide spots of ice compared to other types of roadways. This is because bridges and overpasses are elevated structures that are exposed to air on both the top and bottom surfaces. This exposure allows heat to dissipate more rapidly than it does for regular roadways, which are in contact with the ground and retain more warmth from the earth beneath them. As a result, bridges and overpasses cool down faster, and moisture on these surfaces is more prone to freezing, forming patches of ice.
In contrast, roadways near the tops of hills, while they may also experience cooler temperatures, are generally not as exposed to air as bridges and overpasses. Their temperatures can remain slightly warmer due to their contact with the ground and the potential for natural heat retention. Therefore, although they can still have icy patches, they are less likely to form as quickly or be as widespread as those on bridges.
Roadways paved with asphalt can contribute to ice formation but are not inherently more susceptible to hiding icy patches compared to bridges or elevated roads. Asphalt surfaces do retain some heat, helping to keep them warmer than the air above them. While asphalt can still freeze when temperatures drop significantly, it is less prone to forming ice rapidly compared to the exposed, elevated surfaces of bridges.
The primary reason bridges and overpasses are most susceptible is their open exposure, which allows cold air to circulate around both sides of the surface. This makes them freeze quicker than roadways that are surrounded by land or structures that provide thermal insulation. On freezing, wet days, drivers should be especially cautious when crossing bridges or overpasses as these areas are notorious for black ice, which is difficult to see and can lead to dangerous driving conditions.