When can drivers proceed if a streetcar is stopping to pick up passengers with a safety zone?

The correct answer is based on the specific regulations regarding streetcars and safety zones in Japan. When a streetcar is stopping to pick up passengers, it typically indicates that there is a safety zone in place. Drivers are allowed to proceed through this area, but only under the condition that they slow down. This emphasizes the need for caution and consideration for passenger safety, as pedestrians may be boarding or alighting from the streetcar.

It's important to note that while drivers are permitted to continue driving, they must do so carefully to ensure the safety of any individuals who may be crossing or near the streetcar. This is why simply being allowed to proceed without stopping or only continuing when pedestrians aren't present would not align with safe driving practices. The requirement to slow down signifies that drivers must remain vigilant and prepared to react to any potential hazards.