The U.S. Department of Transportation has released its first Transportation Services Index report nearly two months after DOT Secretary Norman Y. Mineta announced the creation of the monthly economic indicator at the New York Stock Exchange.

Put out by the Bureau of Transportation Statistics, the index measures for-hire transportation industry output, including truck, railroad, air and inland waterways transportation, as well as pipeline transportation and local mass transit.

The TSI tracks changes from 1996, showing that transportation services in December 2003 rose 18.5 percent from 1996. December's increase was the fourth consecutive increase in the new monthly index.

According to Mineta, the results provide a clear indication of how much the strength of the transportation sector mirrors the strength of our economy.

"If you look at the data, every time the TSI heats up, the economy follows," he said.