What 393.11UR means in plain language
FMCSR 393.11UR targets commercial motor vehicles that are missing or have inadequate lighting devices or reflectors. In practical terms, an inspector is looking at whether your rig has the required lights and reflective equipment in the right places and in working condition. "UR" is a sub-classification within the broader 393.11 lighting family, typically flagged when the specific deficiency involves upper rear-mounted lighting or reflector positions.
The regulation exists because visibility is a core safety issue. A trailer or truck cab that can't be seen clearly — especially at night or in poor weather — creates a hazard for every other vehicle on the road. Inspectors are trained to walk the full perimeter of your vehicle and check that every required lighting device and reflector is present and functional.
If you were cited, it means the inspector found something missing or inadequate in that specific lighting or reflector location. The good news is that this violation does not automatically place you out of service, but it does land on your CSA record and carries real consequences for your safety score.
What our enforcement data actually shows
Across 13 million inspections in our database, 393.11UR has generated 4,851 all-time citations. In the last 12 months alone, our inspection records show 3,188 citations — meaning roughly 66% of all citations for this code have occurred in just the past year, which signals sharply rising enforcement activity. The last 90 days alone produced 733 citations.
Despite that volume, the out-of-service rate for 393.11UR is 0.0% — all 4,851 citations in our database resulted in the driver continuing down the road. Compare that to the all-FMCSR average OOS rate of 31.4%, and it's clear that inspectors treat this as a document-and-move-on violation rather than a pull-you-over-and-park situation. You will not be parked for this citation, but you will carry a CSA severity weight of 3, which accumulates on your safety measurement system profile.
Looking at the monthly trend, citations have been consistently elevated: our data shows 297 in October 2025, 299 in January 2026, and a peak of 326 in March 2026. Enforcement is not seasonal or sporadic — it is a sustained, high-frequency pattern. This code ranks #346 out of 3,036 FMCSR codes by all-time citation volume, placing it firmly in the top 12% of all cited regulations nationwide.
Who gets cited most
The geographic picture in our inspection records is striking. Over the last 180 days, Texas accounts for 1,476 citations — by a wide margin the most active enforcement state for this code. New Mexico is a distant second at 25 citations, followed by Illinois at 23 and Iowa at 16. Kentucky rounds out the top five with just 1 citation in the same period.
The OOS rate is 0.0% across all five states, so there is no meaningful variation in how inspectors respond once they write the citation — the outcome is a note in the record, not a parked truck, regardless of which state you're in.
On the carrier side, our data shows fleets such as SERVICIO INTERNACIONAL DE ENLACE TERRESTRE SA DE CV (USDOT 818175) with 38 all-time citations and TRANSPORTATION AND CARGO SOLUTIONS S DE RL DE CV (USDOT 779973) with 28 citations appearing at the top of citation counts. The heavy concentration of Mexican-domiciled carriers in the top-cited list, combined with the dominant Texas enforcement numbers, is consistent with cross-border inspection activity at ports of entry where equipment condition is scrutinized closely.
How severe is this compared to similar codes
Putting 393.11UR in context within the Vehicle Maintenance category helps calibrate how seriously to take it. Consider three peer codes from our database:
393.9(a) — Inoperable required lamps has 660,737 all-time citations and a 15.4% OOS rate. That's a code with over 136 times the citation volume of 393.11UR and a genuine risk of being parked. If an inoperable lamp is severe enough to park drivers 15.4% of the time, it shows that lighting violations as a family carry real enforcement weight — 393.11UR just happens to sit at the non-OOS end of that spectrum.
396.3(a)(1) — Inspection, repair, and maintenance (general) has 236,919 citations and a 45.3% OOS rate — the highest OOS rate among the peer codes in this category. This code is frequently cited alongside 393.11UR (our 90-day data shows 132 shared inspections), which means an inspector who writes you for lighting often also looks hard at whether your maintenance program is adequate.
393.11 — Lighting devices/reflectors (the parent code) has 179,734 citations and a 1.8% OOS rate. The sub-code 393.11UR sits inside this family at 0.0% OOS, confirming that the "UR" classification is treated as a lower-severity variant even within an already relatively mild category.
How to avoid it
The co-occurring violation data from the last 90 days is the clearest guide to what inspectors are finding alongside 393.11UR. Use these patterns to build your pre-trip routine:
-
Walk the full rear perimeter before every dispatch. 393.9 (Inoperable Required Lamp) appeared in 317 of the same inspections as 393.11UR in the last 90 days. If your rear lamps are out, your reflectors are likely the next thing an inspector checks. Confirm every required lamp is illuminated and every reflector is clean, undamaged, and in its required position.
-
Check trailer coupling and towing connections. 393.55E (Coupling device/towing methods defective) appeared in 189 shared inspections. A loose or damaged coupling often means the rear of the trailer took stress or impact — exactly the kind of event that cracks or dislodges reflectors. If your fifth wheel or pintle hook area shows wear, inspect the rear reflector housings too.
-
Inspect brake tubing and air lines at the same time. 393.45B2UV (Brake tubing/hoses inadequate) showed up in 160 co-occurring inspections. Brake line routing often runs alongside rear lighting wiring harnesses. Chafed or damaged lines in that area can mean wiring damage that kills your lighting circuits.
-
Don't overlook your windshield and cab lighting. 393.78 (Windshield condition defective) appeared in 151 shared inspections. Inspectors doing a thorough check on one item routinely move to adjacent systems. Clean your lenses and check your marker lights while you're at the front of the cab.
-
Know your equipment. Freightliners (1,634 citations), Kenworths (742), and Peterbilts (525) top the cited vehicle makes in our database. These are high-volume platforms, but their age and mileage distributions in the fleet mean lighting connectors and reflector mounts wear faster than on newer units. If you run one of these makes, add a dedicated lens-and-reflector check to your pre-trip, not just a glance.
-
Document your pre-trip in detail. Because 393.11UR carries a CSA severity weight of 3, a pattern of even "minor" lighting citations compounds quickly on your safety score. A written pre-trip log showing you checked lighting systems is your first line of defense in a DataQ challenge if you believe the citation was written in error.