What is the purpose of warning signs on bridges?

The primary purpose of warning signs on bridges is to alert drivers of hazardous conditions. These signs serve as crucial safety measures, providing timely information that can prevent accidents and enhance the safety of both drivers and pedestrians. For instance, warning signs can indicate slippery surfaces, low clearance, or structural concerns that may be present due to bridge age or wear.

In contrast, while other aspects such as visual appeal or historical significance might be related to a bridge's overall context, they do not serve the essential function of keeping drivers informed about potential dangers. Speed limit signs, while important, are not classified specifically as warning signs and instead fall under regulatory signage. The focus of warning signs is unequivocally on safety and hazard awareness, making their role critical in bridge management and operation.