Controlled Substances/Alcohol10Non-OOS· SMS Appendix A v3.20
392.4(a) is a Drugs violation under 49 CFR §392.4(a). It falls in the Controlled Substances/Alcohol BASIC with a severity weight of 10/10. Nationally it was cited 619 times in the last five years, with an OOS rate of 93.4%.
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National roadside inspection stats
as of 6/20/2026
Inspections
547
that found this code
Violations
619
total written
OOS rate
93.4%
578 OOS
Source: FMCSA roadside inspection data (last 5 years). The OOS rate is the share of these violations that led the officer to mark the driver or vehicle out of service.
Violation group
Drugs
Regulation §
392.4(a)
Severity weight
10
Used in SMS
Yes
Status
Active
Updated
6/20/2026
Last updated June 2026
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392.4(a) is the FMCSA roadside-inspection violation code for "Driver uses or is in possession of drugs", part of the Drugs group, cited under 49 CFR §392.4(a).
What BASIC does 392.4(a) affect?
392.4(a) falls under the Controlled Substances/Alcohol BASIC in the FMCSA Safety Measurement System (SMS).
What is the CSA severity weight of 392.4(a)?
392.4(a) carries a severity weight of 10 out of 10. Higher weights indicate violations more closely tied to crash risk, and they count more toward a carrier's Controlled Substances/Alcohol score.
Is 392.4(a) an out-of-service (OOS) violation?
No. 392.4(a) is not an out-of-service violation, so on its own it does not trigger an out-of-service order at the roadside.
How many CSA points does 392.4(a) add to a carrier's score?
The point contribution of 392.4(a) depends on its severity weight (10/10) multiplied by a time weight of 3, 2, or 1 based on how recent the inspection is. You can calculate the exact contribution with the CSA points calculator.
Can 392.4(a) be challenged through DataQs?
Yes. If you believe 392.4(a) was recorded in error, you can file a Request for Data Review (RDR) through the FMCSA DataQs system with supporting evidence. A successful challenge can remove or correct the violation on your record.