What is the minimum visibility requirement for clearance lights under normal atmospheric conditions?

The minimum visibility requirement for clearance lights under normal atmospheric conditions is indeed 900 feet. This standard is established to ensure that the lights can be seen from a significant distance, providing adequate warning to other drivers about the presence of a vehicle, especially in situations where larger vehicles are operating.

The regulation aims to enhance safety on the road by making it easier for surrounding traffic to detect the vehicle's dimensions and position, particularly in low-light conditions or adverse weather. The requirement for 900 feet is indicative of best practices in visibility, thus promoting safer interactions among vehicle operators and reducing the likelihood of accidents related to inadequate visibility.