Update on Rail
Because the calendar was a bit different this year, early weekly data was not directly comparable YoY. It will take a couple of more weeks before the data becomes fully comparable.
So far the gap is closing:
http://www.aar.org/AAR/NewsAndEvents/Freight-Rail-Traffic/2012/01/~/media/aar/weekly_traffic_reports/2012/2012-01-19-railtraffic.ashx
The YoY YTD is +0.9% for carloads, and -1% for intermodal (trailers/containers). Motor vehicles and parts continue very strong, and building materials are strong also. So for now the economic data very definitely doesn't support the theory that the US economy is in a tailspin.
Those who are following rail might also want to follow BTS TSI, which is strongly correlated with the health of the economy. Rail data becomes available long before this index, but this index includes all freight:
http://www.bts.gov/xml/tsi/src/index.xml
There's a graph at the link.