What 393.11TU means in plain language
FMCSR 393.11TU targets commercial motor vehicles that hit the road without the full complement of required lighting devices or reflectors — or with equipment that's present but no longer functioning as required. Think of it as the federal standard that says every lamp, reflector, and marker your truck or trailer is supposed to carry must actually be there and doing its job.
The "TU" suffix distinguishes this specific citation variant from the base 393.11 code. In practice, inspectors write 393.11TU when they find lighting or reflective equipment that is inadequate for the vehicle type being operated — not just inoperable, but insufficient or missing outright. That could mean a trailer reflector bracket that's been torn off, side marker lamps that are absent, or retroreflective tape that has worn away to the point of non-compliance.
The bottom line: if your rig rolls past a weigh station or gets flagged for a Level I inspection and the inspector finds lighting or reflector gaps, 393.11TU is the citation that lands on your inspection report — and it follows your carrier's CSA score.
What our enforcement data actually shows
Here's the first thing you should know if you're standing roadside right now: across 13 million inspections, our records show an all-time out-of-service rate of exactly 0.0% for 393.11TU. Only 1 vehicle out of 15,919 all-time citations was ever placed out of service under this code. For context, the all-FMCSR average OOS rate sits at 31.4%, meaning this code is dramatically less likely to park your truck than the average violation on the books.
That doesn't mean it's consequence-free. Our inspection records show 10,583 citations issued in just the last 12 months, and 2,311 of those came in the last 90 days alone. That pace puts 393.11TU at national rank #163 out of 3,036 FMCSR codes by citation volume — firmly in the top 6% of all codes for how often inspectors write it up. Enforcement is clearly active and consistent.
Looking at the monthly trend data in our database, citations have been running between 860 and 1,023 per month for most of the past year, with February and March 2026 each topping 998. This is not a code inspectors are ignoring. Even if you're not getting parked, you are picking up a CSA severity weight of 3 for every citation — and those points compound if inspections continue.
Who gets cited most
Texas dominates 393.11TU enforcement by a wide margin. Our data for the last 180 days shows 4,682 citations in TX alone, with zero OOS placements. Iowa comes in second at 311 citations, also with a 0.0% OOS rate. Illinois is third at 38 citations. New Mexico, Kentucky, and North Carolina round out the active states with 15, 2, and 2 citations respectively. The OOS rates across all six states are uniform at 0.0%, so there's no meaningful state-to-state variation in whether this violation parks your truck — it generally won't, regardless of where you're stopped.
If you operate cross-border into the U.S. from Mexico, this code is particularly worth watching. Our data shows fleets such as ECO TRANSPORTES INTERNACIONALES SA DE CV (USDOT 558117) with 29 all-time citations and OPERADORA DE TRANSPORTE INTERNACIONAL SA DE CV (USDOT 683428) with 19 citations appearing in the top carriers list. On the domestic side, AGGREGATE HAULERS I L P (USDOT 1021485) leads all carriers with 34 all-time citations. These numbers reflect inspection exposure across large fleets, not a judgment on any individual carrier's practices.
On the equipment side, Freightliner (FRHT) units account for 6,763 all-time citations — far ahead of any other make. Peterbilt (PTRB) follows at 1,861 and Kenworth (KW) at 1,762. If you're running any of these platforms, your pre-trip lighting walk-around needs to be thorough.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, 393.11TU is a relatively low-stakes citation in terms of OOS risk, but it lives in a neighborhood of codes that can hit much harder.
The peer code 393.9(a) — Inoperable required lamps — has accumulated 660,737 citations in our database and carries a 15.4% OOS rate. That's the version of a lighting violation that actually parks trucks at a substantial clip. The base 393.11 — Lighting devices/reflectors — shows 179,734 citations and a 1.8% OOS rate, also meaningfully higher than 393.11TU's 0.0%. So while all three codes deal with lighting compliance, the consequences diverge sharply depending on exactly what the inspector writes.
For broader context, 396.3(a)(1) — Inspection, repair, and maintenance (general) — sits at 236,919 citations with a 45.3% OOS rate. That's the kind of violation that ends your day. The fact that 393.11TU doesn't approach those numbers is some relief, but the CSA severity weight of 3 still accumulates on your record and your carrier's BASIC scores.
How to avoid it
The co-occurring violation data in our database is your roadmap here. In the last 90 days, 393.11TU appeared on the same inspection report as 393.9 (Inoperable Required Lamp) in 1,010 shared inspections — the single most common pairing. That means inspectors who find one lighting issue almost always find another. A thorough, systematic lighting walk-around isn't optional; it's what separates a clean inspection from a multi-violation report.
Here's what to add to your pre-trip routine:
- Walk every light on the trailer and tractor. Check all marker lamps, clearance lamps, and tail lamps before you move. 393.11TU and 393.9 co-occurring 1,010 times in 90 days tells you inspectors are finding multiple lighting failures on the same truck.
- Physically inspect all reflectors and retroreflective tape. Look for missing brackets, cracked reflectors, and worn tape — especially on trailers. Missing or degraded reflectors are exactly what 393.11TU targets.
- Check your windshield. Our data shows 393.78 (Windshield condition defective) appeared on the same inspections as 393.11TU in 566 cases in the last 90 days. A thorough exterior walk-around should include the glass.
- Verify your fire extinguisher is present and serviceable. 393.95A (Emergency equipment — fire extinguisher missing or defective) co-occurred in 395 shared inspections. It takes 15 seconds to confirm it's mounted and charged.
- Confirm periodic inspection documentation is aboard. 396.17C (No proof of periodic inspection) showed up alongside 393.11TU 371 times in 90 days. If your inspection sticker or documentation isn't current, an inspector finding any lighting issue is going to keep looking.
- Pay extra attention on Freightliner, Peterbilt, and Kenworth equipment. These three makes account for the majority of 393.11TU citations in our records — 6,763, 1,861, and 1,762 respectively. If you're driving one of these platforms, treat the lighting check as non-negotiable.
None of these steps take more than a few minutes. The data makes clear that 393.11TU is almost never a trip-ending violation — but it's one of the most consistently cited codes in the country, and every citation adds to your CSA profile.