What is a "stop sign" and its legal requirement?

A stop sign is a traffic control device that requires drivers to come to a complete stop at an intersection before proceeding. This legal requirement is crucial for ensuring the safety of all road users, as it allows drivers to assess oncoming traffic and pedestrians before making a maneuver. The purpose of the stop sign is to reduce the likelihood of collisions at intersections by enforcing a full stop, allowing drivers to check for other vehicles or pedestrians that may be using the roadway. This regulation is mandated by traffic laws, making it a necessary rule for drivers to follow to maintain order on the roads.

In contrast, the other options do not accurately represent the function and legal obligations associated with a stop sign. A sign that advises drivers to slow down does not communicate the necessity of a full stop, and a sign indicating that drivers should speed up directly contradicts traffic safety principles. Additionally, a sign that is optional for drivers to obey does not reflect the legal authority of stop signs, which require compliance to promote safe driving practices.