State highways are major roads that are maintained by individual states in the United States. They connect cities, towns, and rural areas, facilitating transportation and commerce. Each state has its own system of highways, which are often numbered for easy identification. These highways can vary in size and capacity, ranging from multi-lane expressways to smaller two-lane roads. They play a crucial role in the overall transportation network, linking to interstate highways and local roads, and are essential for travel, emergency services, and the movement of goods across the state.