When the U.S. federal government shuts down, the effects extend beyond Capitol Hill. Travelers feel it first at airports, passport centers, and some of the nation’s most visited parks and museums. Fortunately, flights do not stop, and airports remain open. However, essential services operate with less support, and that can lead to delays, longer lines, and reduced hours for some programs. Therefore, understanding what changes—and what does not—can help you plan ahead and protect your trip.