What must a driver do when a traffic signal is out?

Answer: A — Treat the intersection as a four-way stop

When a traffic signal is out, the appropriate action for a driver is to treat the intersection as a four-way stop. This means that all vehicles approaching the intersection must come to a complete stop, assess the situation, and proceed in a manner that follows the rules of yielding the right of way, just as they would at a stop sign. This approach helps ensure safety and order at an intersection that is typically governed by signals, allowing drivers to interact predictably. When signals fail, creating a temporary stop scenario helps prevent confusion and potential accidents, as all drivers understand the protocol of stopping and yielding based on the first-come, first-served principle. The other options suggest different methods of navigating the intersection. Proceeding with caution may not provide the necessary safety measures that a four-way stop ensures. Relying on other drivers could lead to misunderstandings and mishaps, as not all drivers may react responsibly or in a coordinated way without the signals guiding their actions. Waiting for emergency services to direct traffic is typically unnecessary unless an officer is present; drivers should be prepared to manage the intersection themselves under these conditions. This underscores the importance of adhering to established traffic laws, even when circumstances change unexpectedly.