Blue signs along the highway typically indicate:

Blue signs are service signs. They direct drivers to gas stations, food, lodging, hospitals, rest areas, campgrounds, and other services available at upcoming exits. They make it easy for travelers to find what they need without local knowledge. Brown signs serve a similar function but for recreational, cultural, and scenic destinations: parks, historical sites, museums, viewpoints. The clear color coding helps drivers scan signs at highway speed: green is where you are going, blue is where you can stop, yellow is what to watch out for, orange is construction. Service signs sometimes show the actual logos of specific gas, food, or lodging chains at upcoming exits.