http://railfax.transmatch.com/
Here is an example of the information available on this web site. This graph shows Total Traffic for 2008-2009 vs. 2007-2008. There are more graphs and tables on the web site showing data by railroad and by commodity.
Note: This is the last Railfax that we will post because ASI/Transmatch, who provides this data, is discontinuing their free weekly data download. Here is the comment that they included in their last email.
We will be discontinuing our weekly data download with the last week of 2009. The data will be available in a new Railfax Highlights database that will be debuting with the first week of 2010. This new product will include the data that has been in our weekly file as well as the complete 2 year time series to incorporate all restatements issued by the AAR. The Highlights data base will be available on a subscription basis for $65/year (less than $1.25/week). Click HERE to view a sample and subscribe.