A 'Side Road' sign warns drivers about what?

The 'Side Road' sign is primarily used to alert drivers that they may encounter traffic coming from a side road that merges into or intersects with the main road. This warning is particularly important for safety because vehicles coming from the side road may not have a stop sign or signal, which means they might enter the main road unexpectedly. Recognizing this sign allows drivers to be more cautious and prepared for vehicles merging into their path, which is crucial for preventing accidents and ensuring safe driving.

In contrast, other options pertain to different types of traffic signs: A pertains to construction zones, which are typically indicated by specific warning signs that signal ongoing road work; C involves warnings about sharp turns, and these typically depict a curve icon; D refers to speed limit changes, which are indicated by signs displaying the new speed limit. Understanding these distinctions is key to recognizing how different signs function to maintain road safety.