Final answer:
Yes, parking lights can be used as signals as long as headlights are on, but they should not be used as a substitute for turn signals when making turns or changing lanes.
Step-by-step explanation:
Yes, parking lights can be used as signals as long as headlights are on. Parking lights are designed to be used when the vehicle is parked or when it is stationary on the side of the road. They are not as bright as headlights but can still provide some illumination to make your presence on the road known to other drivers. However, it is important to note that parking lights should not be used as a substitute for turn signals when making turns or changing lanes. Turn signals are specifically designed for signaling your intentions to other drivers and provide clearer and more visible indications.