Monthly average of 1996 = 100
Note: TSI is a chain-type index. The TSI total is a single monthly measure of transportation services in the United States. By seasonally adjusting and indexing the separate modal numbers of freight traffic and passenger travel, the TSI portrays the total change in for-hire transportation services.
Source: Compiled by U.S. Department of Transportation, Bureau of Transportation Statistics (BTS), November 2004, available at www.bts.gov/xml/tsi/src/index.xml. Monthly Gross Domestic Product (GDP) Quantity Index numbers are BTS estimates based on quarterly GDP data published by the Bureau of Economic Analysis.