I knew it was only a matter of time before this issue came up with drug tests, but here is an article about the DOT ruling on this issue.
http:// www . jacksonlewis . com/legalupdates/article.cfm?aid-1887
I didn't realize that so many states had decriminalized the use of this. I thought it was only California. (Alaska, California, Colorado, Hawaii, Maine, Michigan, Montana, Nevada, New Mexico, Oregon, Rhode Island, Vermont, and Washington) Federal law still lists the the drug as illegal.