What 393.25B means in plain language
FMCSR 393.25B requires that rear lamps or reflectors on your commercial motor vehicle remain visible and unobstructed. If your tailboard, cargo, or any other load blocks those lights from view, you've violated the regulation.
This is a visibility issue. The inspectors at roadside check whether a driver or another person standing behind your vehicle can see the red lights that signal your presence, braking, and direction changes. When cargo piles up against the back of your trailer, straps hang loose, or a tailgate doesn't close fully, it shadows those lamps. The federal requirement is straightforward: nothing between the light source and the road behind you.
What our enforcement data actually shows
Across our database of 13 million+ roadside inspections, we have recorded 222 all-time citations for 393.25B, with 166 citations in the last 12 months and 25 in the last 90 days. This ranks 393.25B at #1190 of 3,036 FMCSR codes by citation volume—a relatively uncommon violation overall.
The out-of-service rate for 393.25B is 2.7%, meaning only 6 vehicles out of 222 were placed out-of-service for this violation. That rate is dramatically lower than the all-FMCSR average of 31.4%. In practice, inspectors almost always issue a citation and let you proceed; they rarely shut you down on the spot for obscured rear lamps. However, the citation itself will remain on your safety record and may factor into roadside stop frequency and CSA scoring.
The 12-month trend shows enforcement activity picking up in summer and early fall—our records indicate 27 citations in August and 25 in October—then declining through winter and early spring. This pattern suggests inspectors are more attentive to rear-lamp obscuration when loading and cargo-handling intensity is higher.
Who gets cited most
Over the last 180 days, New Mexico leads enforcement with 50 citations (0.0% OOS rate), followed by Texas with 5 citations (0.0% OOS rate) and North Carolina with 4 citations (0.0% OOS rate). All three states have not placed a single vehicle out-of-service for this violation, consistent with the national 2.7% OOS rate.
Our data shows fleets such as Premier Couriers–El Paso Inc, Lechuga Group LLC, and MVT Services LLC each with 2 citations in our all-time records. This spread across many carriers—no single fleet dominates the violation list—suggests the issue is driven by situational factors (cargo type, loading practices, time pressure) rather than systemic fleet negligence.
How severe is this compared to similar codes
Within the vehicle-maintenance category, 393.25B is far less frequently cited than its closest peer. Code 393.9(a), Inoperable Required Lamps, accounts for 660,737 citations with a 15.4% OOS rate—nearly 3,000 times more citations and a six-fold higher OOS rate. Code 393.11, Lighting Devices/Reflectors (the broader lamp category), has 179,734 citations and a 1.8% OOS rate, still more frequent than 393.25B but still relatively lenient on OOS placement.
Code 393.78, Windshield Condition Defective, registers 157,894 citations with only a 0.3% OOS rate—even lower than 393.25B. The pattern across these peer codes is clear: lamp and visibility violations are written frequently but rarely result in OOS orders unless the defect is truly unsafe.
How to avoid it
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Conduct a pre-trip walk-around of your trailer's rear. Look directly at your tail lights, brake lights, and reflectors from behind the vehicle. Ensure no cargo, straps, or tailboard obstruct them. Do this before every departure, especially if you've loaded or reloaded.
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Secure cargo tight against the front of your trailer, not the rear. Distribute weight forward. Loose or shifted loads that slide backward are a common cause. Use load bars or straps to hold pallets and bundles in place.
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Check that your tailgate closes and latches fully. A partially open or misaligned tailgate is a frequent culprit. Make it part of your post-load inspection.
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Watch for hanging straps and bungee cords. After securing a load, verify that no tie-down strap or cord dangles below or behind the tail lights. Tuck them away.
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Clean your rear lights and reflectors regularly. While not strictly about obstruction, our data shows that inoperative lamps (code 393.9TS) commonly co-occur with obscured lamps. Mud, water damage, or corrosion can darken lights; clean them during your pre-trip to catch failures early.
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If you haul certain cargo types (furniture, general commodities, agricultural goods), double-check after each stop. Vibration and road movement can shift loads. The top vehicle makes cited for this violation—Freightliner (FRHT, 63 citations), Utility (UTIL, 22 citations), and International (INTL, 21 citations)—are common in general freight. These rigs are high-volume, high-stop operations where multiple load-unload cycles increase the risk of obscuration.
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Inspect brake components and coupling devices at the same time. Our records show that code 393.55E (Coupling Device/Towing Methods Defective) and code 393.47E (Slack Adjuster Defective) frequently appear alongside 393.25B citations in the same inspection. A thorough pre-trip that addresses brakes and coupling also strengthens your overall vehicle condition.