The objective of this task was to develop a set of national values for total spending on Interstate programs and total spending for Interstate interchanges. The study was accomplished by working with an AASHTO Task Oversight Committee to develop a framework for the analysis, definitions, and reporting periods. The research team sought to obtain the needed information from each state and the District of Columbia for an historical period of eleven years and a planned period covering the next ten years. The study product presents a set of national values and summary statistics that improve understanding of spending for the Interstate Highway system.