The Federal Motor Carrier Safety Administration is seeking comment on a request by an alliance of large motor carriers for an exemption that would permit the carriers to report \u201cactual knowledge\u201d of a truck driver\u2019s positive hair drug test to the agency\u2019s Drug and Alcohol Clearinghouse. The carriers, who belong to a group called The Trucking Alliance, have drug tested tens of thousands of drivers using hair and urine samples, but claim the hair testing method is far more successful in detecting lifestyle drug users who don\u2019t belong behind the wheel of a truck.\nLearn more about your ad choices. Visit podcastchoices.com/adchoices