The purpose of AS 19.05 - AS 19.25 is to establish a highway department capable of carrying out a highway planning, construction, and maintenance program that will provide a common defense to the United States and Alaska, a network of highways linking together cities and communities throughout the state (thereby contributing to the development of commerce and industry in the state, and aiding the extraction and utilization of its resources), and otherwise improve the economic and general welfare of the people of the state.