Why can bridges and overpasses be hazardous during cold weather?

Bridges and overpasses can be particularly hazardous during cold weather because they are typically constructed with materials that lose heat quickly. Unlike regular roadways, which are insulated by the ground beneath them, bridges and overpasses are exposed to air both above and below. This exposure allows cold air to circulate around the structure, causing the surface temperature to drop faster than on regular pavement. As a result, ice can form on bridges and overpasses before it appears on other road surfaces, leading to potentially dangerous driving conditions.

This characteristic makes it crucial for drivers to be prepared for slippery conditions when approaching these structures, even if the surrounding road appears clear. Awareness of this difference helps ensure safer driving practices during winter weather.