Sources:
ATA Truck Tonnage Index Fell Another 2.2 Percent in April
Connie Heiss
Truckline.com May 26, 2009 4:30 PM
http://www.truckline.com/pages/article.aspx?id=528/%7b8E1C7279-ED27-4C03-B189-CEEEE26BBB12%7d

Rail Traffic Down Sharply in May
AAR.org, 4 Jun 2009
Tom White
http://www.aar.org/NewsAndEvents/PressReleases/2009/06_WTR/060409_Traffic.a