I’ve seen some e-mail traffic on overweight corridors recently.  Not too long ago, we did an analysis of several overweight corridors in a study we did for the Texas Department of Transportation.  A description of each corridor and the legislation that authorized it are included in the report.  If you are interested, check out page 55 and Appendix F in the report found at this link:  http://tti.tamu.edu/documents/0-5937-1.pdf