What signifies that you need to come to a stop at a light or sign?

A flashing red signal is a clear indication that you must come to a complete stop. This type of signal functions similarly to a stop sign; drivers are required to stop and yield the right of way to other vehicles and pedestrians before proceeding. The purpose of a flashing red light is to alert drivers to an intersection or a situation where caution is needed, ensuring safe navigation through the area.

In contrast, a flashing yellow light indicates that you should slow down and proceed with caution, rather than stopping completely. A solid green light permits you to move forward without stopping as long as it's safe to do so, while a green arrow indicates a specific direction in which to go, granting you the right of way. Therefore, the flashing red signal stands out as the sign requiring a full stop, ensuring safety at intersections and high-traffic areas.