What type of sign indicates the regulation within traffic control systems?

The type of sign that indicates regulation within traffic control systems is represented by white or black signs. These signs are crucial for conveying critical instructions that govern driver behavior, such as speed limits, parking restrictions, and other rules of the road. The use of white or black ensures that these regulatory messages are clear, legal, and easy to understand, which is essential for maintaining safe traffic flow.

In contrast, yellow signs typically serve as warning signs, alerting drivers to potential hazards or changes in road conditions rather than establishing regulations. Blue signs are often used to provide information related to services available to travelers, like rest areas or emergency services, and orange signs are primarily associated with construction and maintenance zones, warning drivers of temporary changes in road conditions. White or black signs are the standard that delineate regulatory messages, making them critical for proper traffic management and safety.