The Dow Jones Transportation Average (DJTA) is a stock market index that tracks the performance of 20 major transportation companies in the United States. It includes firms involved in various sectors such as railroads, airlines, and shipping. The index is used as an economic indicator, reflecting the health of the transportation sector and, by extension, the broader economy. Established in 1884, the DJTA is one of the oldest stock indices and is part of the larger Dow Jones Industrial Average family. Investors often look at the DJTA to gauge trends in economic activity, as rising transportation stocks can signal increased demand for goods and services.