When encountering a robot ahead as indicated by Sign O4, what must you do?

When encountering a robot ahead, as indicated by Sign O4, the appropriate response is to prepare to stop. This sign serves as a warning that there is a traffic control device ahead, such as a traffic light, which regulates the flow of vehicles and pedestrians.

By preparing to stop, you are acknowledging that the robot may be red or that traffic conditions may require you to halt your vehicle. It is crucial to approach such intersections with caution, as failing to prepare to stop can lead to accidents or violations of traffic laws.

This action is important for not only your safety but also ensures the safety of other road users, including pedestrians. Being prepared to stop allows you to respond appropriately to the traffic light signals and any potential changes in traffic conditions at the intersection.