Final answer:
State laws specify the minimum distance at which clearance lights on a vehicle must be visible, often set at 500 feet in clear weather, to ensure the safety of all road users.
Step-by-step explanation:
The question pertains to state regulations concerning the visibility range of clearance lights on vehicles under normal atmospheric conditions. In the context of vehicle equipment laws, clearance lights must be designed to be visible from certain minimum distances to ensure road safety.
The specific distance can vary depending on the state law; however, a common standard requires that clearance lights be visible at a minimum of 500 feet in clear weather conditions. This measure is to ensure that other drivers can reliably see the vehicle, particularly commercial vehicles or trailers, which rely on clearance lights for visibility during nighttime or poor weather conditions.