Final answer:
Road signs are the first indication of potential hazards to road users, designed to alert them and provide advance warning. Traffic signals also regulate traffic flow and enhance safety, especially at busy intersections and areas with high accident rates.
Step-by-step explanation:
The first indication to a road user that there is a potential hazard ahead can come from various sources. Among the options provided, road signs are specifically designed to alert drivers, cyclists, and pedestrians of potential dangers. They are strategically placed to provide advance warning and allow enough time for road users to take necessary precautions. For example, signs indicating a sharp turn, school zone, or wildlife crossing serve as clear visual cues about upcoming hazards. Traffic signals also play a critical role in regulating vehicle and pedestrian traffic, ensuring that both can navigate intersections safely. These signals are essential where pedestrian safety is an issue, especially when students and others need to cross busy intersections to reach campuses or other destinations. Installing a traffic signal can also be a powerful measure to reduce accidents and enhance general safety by compelling vehicles to adhere to speed limits and yield to pedestrians, thereby lowering the incidence of accidents in high-risk areas.