What 392.5A2-UI means in plain language
If you are stopped at roadside and an inspector has reasonable cause to believe you are operating your commercial motor vehicle while under the influence of an intoxicating beverage—whether beer, wine, spirits, or any other intoxicating drink—you will be cited under 392.5A2-UI. The regulation does not set a specific blood alcohol concentration threshold the way some state DUI laws do. Instead, it targets the condition of impairment itself from any intoxicating beverage.
This is distinct from having alcohol in your possession while on duty (which is a separate violation, 392.5A3) or from consuming alcohol within 4 hours before operating (392.5A1). The focus here is whether you were actually impaired at the time you were operating the vehicle.
What our enforcement data actually shows
Across our 13 million+ inspection records, 392.5A2-UI carries one of the highest enforcement stakes in the entire FMCSR system. Our data shows an out-of-service rate of 97.5%—meaning nearly all drivers cited for this violation are immediately removed from service. For context, the all-FMCSR average OOS rate is 31.4%, so this code sits far above the typical enforcement outcome.
Enforcement volume remains low in absolute terms but consistent. We have recorded 80 all-time citations in our database for 392.5A2-UI, with 45 citations in the last 12 months and 11 citations in the last 90 days. This ranks 392.5A2-UI at #1489 out of 3,036 FMCSR codes by citation volume—it is uncommon relative to most other violations, but when it is enforced, the consequences are nearly universal out-of-service placement.
Who gets cited most
Our inspection records show enforcement concentrated in three states over the last 180 days. Iowa leads with 9 citations, all resulting in out-of-service placement (100% OOS rate). Texas follows with 5 citations, also at 100% OOS rate. Illinois recorded 4 citations, again with 100% placement out of service.
The uniform 100% OOS rate across these top states underscores the rigid enforcement standard for this violation. Whether you are cited in Iowa, Texas, or Illinois, the practical outcome is the same: immediate removal from service.
Our all-time citation data shows individual carriers such as C R England Inc (USDOT 28406), Melton Truck Lines Inc (USDOT 34666), and Decker Truck Line Inc (USDOT 53824) appearing in the records, each with one citation. No single fleet dominates the violation pattern, suggesting impairment enforcement affects operators across the industry without clustering in a particular carrier segment.
How severe is this compared to similar codes
392.5A2-UI sits within the Controlled Substances/Alcohol enforcement category alongside several related codes. Comparing severity by citation volume and OOS rate reveals the hierarchy:
Drug-use violations (392.4A-DOSP and 392.4(a)) generate far higher citation counts—3,947 and 3,919 respectively—with OOS rates of 95.9% and 96.9%. These codes are roughly 50 times more frequently cited than 392.5A2-UI. However, alcohol-specific codes cluster tightly around the 97.5% mark: 392.5A3-IDUI (possession of alcohol while on duty) saw 1,478 citations with a 96.8% OOS rate, and 392.5(a)(2) (BAC 0.04 or higher) recorded 778 citations with a 99.2% OOS rate. The message is clear—once you are cited for any alcohol-related operating violation, out-of-service removal is nearly automatic.
How to avoid it
The surest way to avoid 392.5A2-UI is straightforward: never operate a commercial motor vehicle if you have consumed any amount of alcohol before or during your shift.
Our data reveals patterns worth noting. Among co-occurring violations in the last 90 days, 392.5A3 (possession of alcohol while on duty) appears in 6 shared inspections, suggesting that drivers cited for impairment often also had alcohol in their cab. This points to a prevention principle: do not carry alcoholic beverages in your vehicle during your work time, and do not consume any alcohol before or immediately before your shift.
392.5A1 (consuming alcohol within 4 hours before operating) co-occurred in 2 inspections, underlining the importance of a clear time buffer between drinking and getting behind the wheel. Build in a minimum 4-hour gap, and be honest with yourself about whether you are truly impaired-free after that window.
Fatigue-related violations (392.2MI and 392.2) co-occurred in 4 shared inspections, which may reflect inspector focus on overall driver fitness. Make sure you are rested before your shift; do not attempt to mask fatigue with stimulants, and do not self-medicate with alcohol to help you sleep.
Finally, the vehicle makes most frequently cited—Freightliners (29 citations), Utilities (11), Volvos (10), and Peterbilts (10)—suggest no particular truck type is exempt from enforcement. Before you operate any commercial vehicle, perform a clear-headed pre-trip inspection and verify your fitness for duty. If you have any doubt about your condition, inform your dispatcher and do not operate.
The 97.5% out-of-service rate is not a consequence you walk away from lightly. It will be recorded on your driving history, may affect your insurability, and can lead to termination from your carrier. The only safe choice is not to drive under the influence, period.