Today, security is one of the most important issues in U.S. international passenger travel and transportation. The terrorist attacks of September 11, 2001, had an immediate impact on international travel and transportation, and are expected to continue to influence not only the aviation industry but all passenger travel to and from the United States. Following the attacks, for example, overseas travel to the United States declined by 39 percent in October 2001 compared with October 2000, and overseas travel from the United States fell 29 percent1 (USDOC ITA 2002a, 2002b, 2002c). International air enplanements and border crossings also fell significantly in September and October 2001. Not surprisingly, however, international travel is slowly returning to its pre-September 11 levels as traveler confidence is restored.

Prior to the attacks, international passenger travel to and from the United States showed steady growth in most markets, for an average annual increase of 2 percent between 1990 and 2000. During this period, overall U.S. outbound passenger travel rose from 131 million trips to 171 million, a 31 percent increase. At the same time, overall inbound passenger travel to the United States grew by 6 percent from 184 million trips to 195 million (table 1). International travel continues to hold a large share of U.S. economic activity and tourism.

Although U.S. international passenger travel has seen dramatic changes in recent years, there have also been patterns of continuity. Same-day travel with Canada and Mexico accounts for the majority of U.S. international travel and saw slow but steady growth during the 1990s. Overnight travel to and from other countries grew notably during this same period from 84 million trips to 112 million, a 33 percent increase2 (table 2).

Because of the terrorist attacks, new security procedures and concerns are already placing increased demands on the nation's transportation network and posing new challenges for the transportation sector. In particular, the key gateways-airports and land border crossings-that primarily service these travel flows continue to be affected. Like other transportation demands, any changes in international travel will also affect the U.S. transportation network in terms of safety, capacity, scheduling, and congestion.

This report examines transportation's role in facilitating international travel and the demands such travel places on the U.S. transportation system. It provides an overview of U.S. international travel, reviews regional trends, and highlights significant changes in air travel. It also looks at some of the new challenges facing the international transportation community in general, and the aviation industry in particular, following the September 11 terrorist attacks. Although it is still too early to fully assess the long-term effects of these attacks, passenger mobility and international travel could be affected on several levels, including changes in travel volumes, continued adjustments in security and safety procedures, carrier modifications in scheduling and pricing, and shifts in geographic patterns of travel. This report uses a variety of data sources to show longer term trends in U.S. international passenger travel from 1990 to 2000, and where available employs recent data to assess the immediate impact of the events of September 11 on U.S. international passenger travel.


1 At the time this report was written, comprehensive data were not available to illustrate the impact of the September 11 attacks on all U.S. international travel, both same-day and overnight for North America and overseas, and for all modes of transportation. Where available, post-September 2001 data are used to assess the impact of September 11 on U.S. international passenger travel.

2 Overnight travel includes overseas and North American travel of more than one day. In 2000, overseas overnight trips totaled 53 million and North American overnight trips totaled 59 million.