Guidance: An employer may perform any testing provided it is consistent with applicable law and agreements, and is not represented as a DOT test.

Guidance: No. The drug and alcohol testing is employer-based and proof of compliance must be maintained by the employer. The only certificate that is required to be in the driver's possession while operating a CMV is the medical examiner's certificate required in §391.41(a) and, if applicable, a waiver of certain physical defects issued under §391.49.