Answer :
Final answer:
Most warning signs are diamond-shaped with black letters or symbols on a yellow background and are used to alert drivers of potential road hazards.
Explanation:
Most warning signs are diamond-shaped with black letters or symbols on a yellow background. These signs are designed to alert drivers to potential hazards or changes in conditions on the road ahead. Unlike pictograms that are standardized by OSHA, these warning signs are standardized by the Department of Transportation for road safety. Regulatory signs, on the other hand, are typically rectangular and have a white background with black letters or symbols. Service signs usually have a blue background with white letters or symbols, and destination signs are often green with white letters or symbols.