What is the primary action to take upon encountering a stop sign?

The primary action when encountering a stop sign is to stop completely before the sign. This requirement is in place to ensure the safety of all road users, as it allows drivers to assess the situation at intersections where visibility may be limited. Stopping fully provides the opportunity to check for oncoming traffic, pedestrians, or cyclists, thus reducing the risk of accidents.

A complete stop at a stop sign is a legal requirement in most jurisdictions, including Missouri. Rolling through the sign or simply slowing down does not fulfill this requirement and can lead to dangerous situations or traffic violations. Yielding only when there are no cars around does not account for unseen traffic or pedestrians and may still pose a danger. Ignoring the sign altogether is also unsafe and illegal, as it disregards traffic control measures designed to protect everyone on the road.