At the beginning of the twenty-first century, the National Park Service (NPS) faces a daunting challenge in its mission: to preserve and protect the natural and cultural resources within the nearly 400 national park units while providing transportation systems adequate to accommodate growing visitation-up from 220 million recreation visits in 1980 to more than 277 million in 2002, an increase of more than 25 percent. Because one traditional response-building additional transportation infrastructure-is no longer considered a sustainable or desirable solution to park access, congestion, and environmental problems, meeting this challenge requires careful transportation planning and consideration of new methods and technologies. One such set of technologies, Intelligent Transportation Systems (ITS), represents practical alternatives to building new or expanded roads as the only solution to meeting growing travel demand. NPS has already deployed ITS technologies in several parks; experiences to date indicate that there are many other circumstances under which ITS has the potential to help NPS better manage its transportation systems.