UK Driving Theory Practice Exam

Using headlights during the day is mandatory in the UK when visibility is poor. This rule is designed to enhance safety on the roads, ensuring that vehicles are visible to other road users in conditions where sight is limited. Poor visibility can be caused by various factors, including fog, heavy rain, snow, or even when driving through dark tunnels.

By using headlights when visibility is poor, drivers significantly reduce the risk of accidents, making it easier for other drivers, cyclists, and pedestrians to see them. It helps provide a clear signal to others on the road about the vehicle's presence, thereby promoting safer driving conditions.

Other scenarios such as heavy traffic or specific months of the year do not universally require the use of headlights during the day, and using them at all times could be unnecessary and might cause glare to other drivers. Each of these conditions would not align with the primary objective of ensuring visibility in adverse conditions, which is the core focus of the correct answer.