Which color is usually associated with regulatory signs that enforce rules to drivers?

The color red is universally recognized as a signal for stopping or caution in various contexts, especially in traffic control. Regulatory signs, which are designed to enforce rules that all drivers must adhere to, often utilize red to convey imperative instructions clearly. This includes stop signs, yield signs, and various prohibitory signs, which all serve to ensure safety and compliance on the road. The distinctive and attention-grabbing nature of red helps to communicate critical information that must be heeded promptly by drivers.

In contrast, green often signifies guidance or provides information about direction and permissible actions like go or proceed, making it less suitable for regulatory commands. Yellow is typically used for warning signs, indicating caution rather than direct regulations. Blue is used for informative signs, such as those indicating services or facilities, but does not convey the same urgency or necessity for compliance as red does. Thus, red is the appropriate color associated with regulatory signs enforcing rules to drivers.