What 393.25(b) means in plain language
FMCSR 393.25(b) requires that your truck's rear lamps and reflectors remain visible and unobstructed. If your load, tailboard, or any other obstruction blocks these lights from being seen by following drivers, you're in violation.
This is about safety: rear lights tell drivers behind you that you're there, that you're braking, and where your vehicle ends. When cargo piles too high, shifts during transit, or isn't properly secured, it can hide these critical warning devices. Inspectors check whether every required rear lamp and reflector can be seen clearly from a normal viewing distance.
The violation is straightforward—either your rear lamps are visible or they aren't. If an inspector finds them obscured at roadside, you get cited. Unlike some lamp violations that result in out-of-service orders, this one typically doesn't: our inspection records show an 8.0% out-of-service rate, well below the all-FMCSR average of 31.4%.
What our enforcement data actually shows
Across our 13 million+ real roadside inspection records, 393.25(b) has generated 528 all-time citations nationally. This ranks the code at #896 of 3,036 FMCSR codes by citation volume—a relatively uncommon violation, but not negligible.
In the last 12 months and last 90 days, our database shows zero citations for 393.25(b). This suggests the violation is either becoming rarer or clustering in specific periods or regions. Of the 528 citations ever recorded, inspectors placed only 42 vehicles out of service, yielding an 8.0% out-of-service rate. That's substantially lower than the typical FMCSR code: on average, 31.4% of violations result in an immediate roadside removal from service.
The reason is practical: if your rear lights are obscured but functional, you can usually clear the obstruction, pass re-inspection, and continue your trip. You don't need major repair or a tow.
Who gets cited most
Our inspection records do not include state-level breakdowns in this dataset, so we cannot name the top three states by citation count. However, the top carriers cited for 393.25(b) include TROY C GERLACH (USDOT 771864) with 5 citations and LYNDEN ICE CO LLC (USDOT 1891369) with 4 citations. These fleets show that the violation occurs across different industries and carrier types—it's not confined to one business model.
Vehicle makes most frequently cited for 393.25(b) tell an important story: Freightliners (FRHT) dominate with 40 citations, followed by Peterbilts (PTRB) with 21 and Kenworths (KW) with 17. The pattern suggests that larger Class 8 tractor units are cited more often, likely because they pull longer trailers and carry higher or more irregular loads. Ford, International, Wanchuk, Utility, Volvo, and Mack units also appear in the citation records, showing the violation is not limited to any single manufacturer.
How severe is this compared to similar codes
To understand where 393.25(b) sits in the vehicle maintenance landscape, compare it to related lamp and inspection violations:
393.9(a) — Inoperable required lamps has generated 660,737 citations with a 15.4% out-of-service rate. That code catches lamps that don't work at all; our data shows it's about 1,250 times more common than 393.25(b). When a lamp is broken, inspectors are more likely to place you out of service.
393.11 — Lighting devices/reflectors produced 179,734 citations with only a 1.8% out-of-service rate. This broader code covers many lighting defects; 393.25(b) is a subset focusing on obstruction rather than defect.
393.9 — Inoperable Required Lamp (the parent code category) shows 180,097 citations and a 6.9% out-of-service rate, close to 393.25(b)'s 8.0%, indicating that obstruction violations and inoperable lamp citations have similar roadside outcomes.
How to avoid it
Preventing a 393.25(b) citation starts before you load and continues during your pre-trip inspection:
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Load securely and within height limits. Before leaving the dock, ensure your cargo is properly secured and doesn't extend beyond the tailboard or sides of the trailer. If you're hauling pallets, boxes, or bulk material, confirm it's stacked and tarped so nothing hangs over the rear edge.
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Check rear lamps and reflectors during pre-trip. Walk around the back of your trailer in daylight. Look at each rear lamp—marker lights, brake lights, reflectors—and confirm they're clean, unobstructed, and visible. Wipe off dirt or condensation. This takes two minutes and prevents a citation.
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Inspect after loading and before departure. Even if you loaded cargo yourself, do a final walk-around. Cargo can shift slightly during docking or when you back up. Make sure nothing has drifted to block the rear.
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Watch for loose or falling cargo. During transit, especially on bumpy roads, cargo can shift. If you suspect your load has moved, pull over safely and check the rear before an inspector does.
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Pay attention to high loads and irregular shapes. Freightliners and Peterbilts, the most frequently cited vehicles in our data, often haul tall or bulky freight. If your load is taller than usual, taller than the trailer sides, or has protruding edges, plan extra time to confirm rear visibility.
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Keep your trailer in good condition. Damaged or missing reflectors, corroded lamp housings, or bent tailboards reduce the chance that lamps stay visible. Routine maintenance catches these before they become obstruction problems.
A 393.25(b) citation is fixable on the spot—clear the obstruction, show clean rear lights, and move on. But it's also preventable with a 60-second pre-trip check and attention to load placement. Our data shows it's uncommon, which means most drivers and fleets handle it correctly. You can too.