Since the early 1990s, the Federal Motor Carrier Safety Administration (FMCSA) and its predecessor agency has defined drug and alcohol testing rules and regulations for employees who drive commercial trucks and buses that require a commercial driver’s license (CDL). These regulations identify who is subject to testing, when they are tested and in what situations. Generally, all CDL drivers who operate commercial motor vehicles subject to the CDL requirements on public roads in the U.S. are performing safety-sensitive functions and are subject to DOT drug and alcohol testing (§382.103). This includes all full-time, part-time, intermittent, backup and international drivers. Regulations issued by FMCSA are published in the Federal Register and compiled in the U.S. Code of Federal Regulations (CFR).

DOT Drug and Alcohol Tests

Pre-employment — An employer must receive a negative drug test result before permitting a CDL driver to operate a CMV (§382.301).

Post-accident — Drug and alcohol tests may be required after crashes according to the chart below (§382.303)

Random — CDL drivers must be randomly tested throughout the year (§382.305); an employer who employs only himself/herself as a driver, who is not leased to a motor carrier, shall implement a random testing program of two or more covered employees in the random testing selection pool as a member of a consortium (see §382.305 interpretation 11).

Reasonable suspicion — Drivers who appear to be under the influence of drugs or alcohol can be immediately tested (§382.307). You need to train CDL driver supervisors to detect the symptoms of driver impairment (§382.603).

Return-to-duty — Required for drivers who tested positive, refused, or otherwise violated the prohibitions of 49 CFR Part 382 Subpart B; and who have completed the return-to-duty process with a DOT-qualified substance abuse professional. This test is directly observed, and a negative result is required before resuming driving duties (§382.309 and §40.305).

Follow-up — Required for drivers who tested positive, refused, or otherwise violated the prohibitions of 49 CFR Part 382 Subpart B; and who have completed the return-to-duty process with a DOT-qualified substance abuse professional, and have tested negative for a return-to-duty test. This testing is prescribed by the substance abuse professional for a minimum of 6 directly observed tests in 12 months, but can be extended an additional four years (§382.311 and §40.307).

Back – to – Work — If a driver has been removed from a DOT random testing pool for more than 30 days, the employer must give the driver a pre-employment test and a negative test result must be received before the driver may operate a commercial motor vehicle (CMV). If less than 30 days has passed since the driver was under the DOT random testing program, the employer may re-employ the driver without a pre-employment drug test.