With the number of airplane passengers using U.S. airports expected to grow to almost 1 billion by the year 2015, ground access to U.S. airports has become an important factor in the development of our nation's transportation networks. Increases in the number of passengers traveling to and from airports will place greater strains on our nation's airport access roads and airport capacity, which can have a number of negative economic and social effects. U.S. transportation policy has generally addressed these negative economic and social effects from the standpoint of individual transportation modes and local government involvement. However, European transportation policy is increasingly focusing on intermodal transportation as a possible means to address congestion without sacrificing economic growth. This book addresses the development of intermodal capabilities at U.S. airports, including (1) the roles of different levels of government and the private sector; (2) the extent such facilities have been developed; (3) benefits, costs, and barriers to such development; and (4) strategies to improve these capabilities.