When may parking lights be used?

Parking lights are designed primarily for use when a vehicle is parked, particularly in conditions where visibility may be reduced, such as on a roadway at night or in low-light situations. The use of parking lights alerts other drivers to the presence of the parked vehicle, helping to prevent accidents. They are not intended for use while driving, except in specific circumstances that may be covered by local laws or regulations.

The other choices represent scenarios where using parking lights would not be appropriate. For instance, parking lights are not meant to replace headlights during nighttime driving, as visibility is paramount during those conditions and headlights provide necessary illumination for both the driver and other road users. Similarly, while fog can impair visibility, using parking lights alone is insufficient and does not meet the requirements for safe driving in adverse weather. In heavy traffic, it is important to use the appropriate signaling devices such as turn signals and headlights to navigate safely and communicate intentions to other drivers. Hence, parking lights serve their primary function when a vehicle is stationary and not actively in traffic.