The predictive power of an experimental transportation output index

A monthly output index for the US Transportation sector over January 1979-June 2003 is reported covering air, rail, water, truck, transit and pipeline activities. Separate indexes for freight and passenger are also constructed. The strong cyclical movements observed in the transportation output appear to be well synchronized with the NBER-defined recessions and growth slowdowns of the US economy. The series reflects the profound impact of 9/11 on the transportation sector, especially on the airlines. By December 2002 it has reached its historical peak. Given the observed relationship of the transportation output with the economy, the recent upward trend in the freight transportation strongly suggests that both the sector and the overall economy have recovered from their latest slump.