§392.4 prohibits a driver from being on duty while using, possessing, or under the influence of any Schedule I substance, amphetamine, narcotic, or other controlled substance listed in §392.4(a). The prohibition is independent of the §382 testing regime — a §392.4 finding can be cited from observation alone, without a positive test result.
Severity weight + OOS
Severity weight 10 in the Unsafe Driving BASIC — the maximum. A driver cited under §392.4 is placed out of service for 24 hours under the North American Standard Out-of-Service Criteria. The driver may also face §382.215 use-prohibited status and §383.51 CDL disqualification depending on the substance and the testing follow-through.
Carrier exposure
§392.4(b) requires the carrier to require compliance — knowingly permitting a driver to operate in violation of §392.4 is itself a violation, and pattern findings flow into both the Unsafe Driving and Controlled Substances & Alcohol BASICs.
How to prevent it
- Run §382.701(a) pre-employment full queries before any safety-sensitive assignment.
- Treat reasonable-suspicion observations as §382.307 triggers — supervisors must be trained per §382.603.
- Remove a driver from safety-sensitive functions in writing the moment §392.4 is suspected; the SAP referral under §40 Subpart O starts then.
How Roadworthy HQ helps
§392.4 findings logged in Roadworthy HQ trigger an immediate driver-status change, lock dispatch, route the §382.215 prohibited status through the Clearinghouse query log, and preserve SAP and return-to-duty documentation against §40 Subpart O retention.