This study assesses the travel performance, trade, and economic development impacts directly related to completing the Appalachian Development Highway System (ADHS). The ADHS is the first highway system authorized by Congress for the purpose of stimulating economic development. The ADHS is a 3,571-mile near-interstate grade highway system composed of 31 corridors located in 13 Appalachian states with 3,090 eligible for improvement. The system is approximately 85 percent finished and the completion will link the whole system into an integrated network connecting to national markets and trade flows. The study assesses how the corridor improvements will enhance the connectivity of the Appalachian people and businesses to other highway facilities, multimodal transportation, and markets (specifically labor markets and commuters, buyers and suppliers, and tourism).