Final answer:
When a car has stopped at a crosswalk, you should stop and wait until the car moves, ensuring pedestrian safety and compliance with traffic laws.
Step-by-step explanation:
If a car in the next lane has stopped up ahead at a crosswalk, the appropriate action to take would be to stop and wait for the car to move. The car may have stopped for a pedestrian crossing the street, and it is essential for safety reasons to wait until the path is clear. It is both illegal and unsafe to honk your horn and pass the car, speed up and pass the car quickly, or even to proceed with caution because you may not be able to see a pedestrian that is crossing. This practice is part of ensuring pedestrian safety and adhering to traffic laws concerning crosswalks.