Shipping indexes are some of the best leading indicators of economic health. If there is demand for goods, this will show up in the shipping data. Lower shipping and traffic volume can point to a slowdown. At the same time, the data can by noisy month to month and there is seasonality in demand. Look for a multi-month trend and the rate of change. Rail freight intermodal traffic has been slowing for several consecutive months. Note that the root cause of various recessions is usually very different. Sometimes they come from real estate, a bubble in a particular sector, a commodity shock, are purposely initiated by central banks to fight inflation, wars/external conflicts, and so on. Rail freight and other shipping indexes are just one slice of the puzzle.