Box 1
International Travel Data

Multiple data sources must be used to track U.S. international travel and transportation trends. These data may be collected for administrative/regulatory purposes, from air carriers, or through travel surveys. Each provides important information for analyzing U.S. international travel, but no one source is comprehensive. The United States does not conduct an international travel survey for all modes of transportation for both same-day and overnight travel. Both kinds of information are needed to evaluate the impact of these flows on U.S. transportation systems and services. These different data sources use different definitions, time series, and methodologies, which complicate analysis.

Administrative/Regulatory Data

Immigration Data. As part of the immigration documentation process for entry into the United States, the Immigration and Naturalization Service (INS) requires non-U.S. residents entering the country to complete INS form I-94. Residents of some countries, such as Canada, are exempt from filing the I-94 if they stayed in the United States for less than a certain period or within a specific geographic area. To accommodate this gap, the International Trade Administration (ITA) supplements the INS I-94 data with other sources for those countries. Information on returning U.S. residents is collected through INS form 1-92. Information collected from both these forms provide data on the travel volumes of foreign residents from specific countries to the United States as well as the destination countries visited by U.S. residents.

U.S. Customs Data. The U.S. Customs Service collects daily count data of all persons and vehicles entering the United States along the northern and southern borders. These data do not provide travel and trip characteristics. Nor do they identify travelers by nationality, and as such cannot be used to determine how many persons entering the United States are U.S., Canadian, and Mexican residents or residents of other countries. However, the Customs data show the level of entries at particular border-crossing points.

Travel Surveys

Survey of International Air Travelers. To supplement the travel volume figures from the immigration data, the ITA Office of Tourism Industries conducts a Survey of International Air Travelers that provides information on travel and trip characteristics for overnight trips by air.

U.S-Canada and U.S.-Mexico Data. Travel volumes and trip characteristics for same-day travel between the United States and Canada and the United States and Mexico (other than the Customs and INS data mentioned above) are based on travel surveys conducted by Canadian and Mexican government agencies. No comparable data are available from U.S. sources. Overnight travel data between the United States and its North American partners are also available from Canadian and Mexican agencies as is some limited information from the ITA Tourism Industries Office.

For U.S.-Canada travel, data are collected through Statistics Canada's Tourism Statistical Program.The data are based on administrative counts, as well as an international travel survey. The administrative count data track crossings and arrivals, modal characteristics, and nationality characteristics at all Canadian ports of entry on a census basis (except for sampling done at seven land ports to estimate automobile and motorcycle flows). Statistics Canada obtains a more detailed international traveler dataset including trip duration, trip purpose, and trip-taker personal characteristics through the Canadian Customs distribution of questionnaire surveys to travel parties according to a prearranged schedule and subsequent enhancement by sampling.

For U.S.-Mexico travel, the Banco de México uses sample survey methods at specific international airports and border cities to collect total visitor data, as well as statistics for trip duration, income level, trip purpose, transportation modes used, points of departure, and major cities visited .

While Canadian and Mexican sources are used in this report to highlight modal breakdowns for overnight and same-day U.S.-North American travel, the Bureau of Transportation Statistics' (BTS) American Travel Survey (ATS) also reports characteristics of U.S. travel abroad. The ATS, last completed in 1995, provides data for long-distance trips of more than 100 miles, including trips made by U.S. residents to Canada and Mexico. This stricter definition of visitors yields a lower number of American trips to Canada and Mexico as compared with the Mexican and Canadian source data and assigns a higher proportion of trips to air travel. For 2002, BTS and the Federal Highway Administration are jointly conducting the National Household Travel Survey, covering both long- and short-distance travel.

Air Carrier Data

BTS's Office of Airline Information collects air carrier data on international travel and transportation. These include the T-100 segment data collected from nearly 90 U.S. commercial air carriers and cover all scheduled and unscheduled international nonstop commercial traffic arriving and departing U.S. airports for aircrafts of 60 seats or more. Approximately 140 foreign carriers serving or transiting the United States file information similar to that supplied by the U.S. carriers, which is included in the T-100(f) statistics.