Here is a quick mid-year review of the railway role in the US freight market.
The US economic growth measured in GDP change is for this year still is below 2.5%.
While the USA freight railroads still show world class profitability (see their quarterly reports for those details), they are for the most part doing it with productivity management skills rather than with traffic growth.
Attached are a few images that reflect the 2007 to 2013 mid-year freight business volumes.
Download the PDF here: MID YEAR 2013 US Rail Traffic -1 – J Blaze
Reports identifying similar traffic changes in the rest of the globe for railways are generally NOT published in a regular short timeframe like in the US and Canada.