Time-series analysis using monthly data from January 2000 to December 2015 is used to investigate the relationship between transportation and real GDP, controlling for the price of diesel, the amount of money invested in infrastructure, the inflation rate, and the real effective exchange rate. Transportation is proxied with the freight Transportation Services Index. Using Granger-causality, I find that changes in transportation Granger cause changes in real GDP, but not vice versa. It is a one-directional relationship where past values of transportation lead changes in real GDP
