Smelling Trouble? A Supervisor's Guide to DOT Reasonable Suspicion

Being under the influence of alcohol or controlled substances while working is dangerous in any job — but it’s especially dangerous in safety-sensitive positions like CDL driving. That’s why the Department of Transportation (DOT) requires supervisors to complete specific training on how to recognize signs of drug or alcohol use on the job.
What is Reasonable Suspicion?
If you're a supervisor overseeing employees in DOT-regulated safety-sensitive roles, you must be trained and certified. Only trained supervisors can initiate a reasonable suspicion test and remove an employee from duty.
Safety-sensitive roles include anyone whose job, if performed under the influence, could endanger public safety. This includes:
- CDL drivers operating trucks, buses, or hazmat vehicles
- School bus drivers
- Rail, subway, and transit operators
- Pilots and flight attendants
- Vessel crew and captains
- Aircraft and vehicle maintenance personnel
- Pipeline and hazardous materials transport operators
- Dispatchers and controllers in transportation
Scenario: You’re a supervisor, and a driver walks in
smelling of alcohol, slurring their speech, and stumbling. If you haven’t been
trained, you cannot act. You’d need to find a certified supervisor to witness
the behavior firsthand — and by then, the employee may already be behind the
wheel.
That’s why every supervisor in a DOT-regulated role should complete this training — to protect people and prevent disasters.
How Do I Get Certified?
Is all of this really necessary?
So How Can I Stay Safe?
You protect yourself and your company by:
- Knowing what to look out for
- Documenting observations clearly
- Acting consistently and professionally
- Respecting confidentiality
- Applying DOT standards to everyone equally
Do:
- Get trained and certified
- Document using clear, specific, and unemotional language
- Focus on what you personally saw, smelled, or heard
- Require testing as soon as possible after observations
- Hold everyone to DOT standards, regardless of seniority or familiarity
Don't:
- Try to diagnose or judge the employee (You’re not a doctor — you’re a trained observer)
- Use vague or emotional language (No: “he seemed off,” “something felt wrong”)
- Refer someone based on secondhand reports
- Delay action or downplay behavior
- Let personal relationships affect your decision-making
- Gossip about the incident with coworkers
Final Tip: When in doubt, trust the training and the process, not your gut or assumptions. If the signs are there and you’re trained to act, don’t hesitate. Safety depends on you.
Want to get Certified?
Click Here!