In 2008, the World Monuments Fund added US 66 to the World Monuments Watch as sites along the route such as gas stations, motels, cafés, trading posts and drive-in movie theaters are threatened by development in urban areas and by abandonment and decay in rural areas. The National Park Service developed a Route 66 "Discover Our Shared Heritage" Travel Itinerary describing over one hundred individual historic sites. As the popularity and mythical stature of US 66 has continued to grow, demands have begun to mount to improve signage, return US 66 to road atlases and revive its status as a continuous routing.