Final answer:
The sign that directs drivers to slow down and let crossing vehicles and pedestrians pass is a Stop sign or a pedestrian crossing sign. The installation of a traffic signal at busy intersections can drastically improve pedestrian safety and decrease the likelihood of accidents, as seen in the example of Clay Street and Eagle Avenue.
Step-by-step explanation:
The sign used to indicate that drivers should slow down and, if necessary, stop to let vehicles crossing their path go by, especially when pedestrians are present, is a Stop sign or a pedestrian crossing sign. The importance of such traffic control devices becomes apparent in scenarios where pedestrian safety is a concern, and where vehicles tend to disregard speed limits, necessitating measures to ensure the safety of pedestrians who need to cross traffic pathways.
Moreover, the implementation of a traffic signal at a busy intersection, such as the one at Clay Street and Eagle Avenue, shows the positive effects of such measures. Before the signal was installed, there was a troubling pattern of vehicles speeding and pedestrians having to navigate through dangerous traffic conditions. The alarming rise in accidents, some of which resulted in fatalities, was a clear indicator of the need for a traffic signal to manage the flow of vehicles and improve pedestrian safety.
It's through such interventions that pedestrians, including students, can safely cross intersections at designated times, reducing the likelihood of accidents, and improving the overall safety of the area around campuses and other pedestrian-heavy zones.