From the DOT Publication Best Practices for Random Drug and Alcohol Testing.
“Is the boss singling me out? I just did a random last month. Joe never gets tested. I don’t think this thing is random at all!” These concerns are common among many safety-sensitive employees. Many employers have faced court challenges to prove their programs follow a truly random process. In reality, a truly random selection process often results in some employees being chosen several times. Others may never get selected at all. Why does this happen? After each selection, the system returns the employee’s name to the same pool. That individual becomes just as likely as anyone else to be picked next time.
