When a streetcar has stopped at a pedestrian island, what must drivers be cautious about?

When a streetcar has stopped at a pedestrian island, drivers must be particularly cautious of passengers getting on and off the streetcar. This situation creates a high-risk environment because passengers may be crossing the street or moving to board the streetcar, and their visibility may be obstructed by the streetcar itself.

It's crucial for drivers to maintain vigilance in these scenarios to ensure pedestrian safety. Passengers could step into the roadway without warning, posing a danger to both themselves and vehicles. Awareness of their presence allows drivers to respond appropriately, such as slowing down or stopping, to prevent accidents.

The other options do not address the immediate safety concern of passenger movement in the vicinity of the streetcar and may incorrectly suggest that drivers can take liberties or act without caution regarding pedestrian safety.