What major problem do operators face when driving at night?

The primary challenge drivers encounter when driving at night is reduced visibility, which affects their ability to see various obstacles and road users. In particular, the correct response highlights a common concern: the difficulty in spotting bicyclists on the road after dark. Bicyclists may not be as easily illuminated as motor vehicles, making them harder to detect in low light conditions. The combination of darkness and limited reflective gear on bicycles can significantly hinder a driver's perception, leading to potential safety risks.

Given the context of night driving, while the other issues regarding speed judgment, pedestrian visibility, and headlight functionality are relevant and significant, the inability to see bicyclists exemplifies a critical focus for drivers. This is because cyclists often share the road with vehicles and their presence requires extra caution, especially when visibility is compromised. Recognizing this specific hazard can help drivers remain vigilant and adopt safer driving practices during nighttime conditions.