Final answer:
A white painted curb signifies a loading zone for passengers or freight, with specific restrictions often posted nearby.
Step-by-step explanation:
A white painted curb typically signifies a loading zone, but the designated purpose can vary depending on local traffic regulations. To answer the question, a white painted curb marks a loading curb zone for either passengers or freight. It's important for drivers to observe any posted signs near the white curb for more detailed information regarding the limitations and restrictions of the loading zone.