What do blue-colored signs on the highway typically indicate?

Blue-colored signs on the highway are commonly used to indicate information related to services available to drivers. This includes places such as gas stations, restaurants, rest areas, and lodging. For example, a blue sign with a gas pump icon alerts drivers to nearby fuel services. This color scheme is intentionally chosen to create a clear distinction between types of information provided on the road, ensuring that drivers can quickly identify essential services they might need during their travels. The use of blue helps convey a sense of helpful information that is not associated with regulatory instructions or warnings, which are typically indicated by other colors.