What 393.11A1-LSML means in plain language
This violation comes down to one thing: your commercial motor vehicle was missing or had inadequate lighting devices or reflectors at the time of inspection. Federal regulations require that CMVs be equipped with specific lamps and reflective devices in working order — not just installed, but functional and properly positioned.
Reflectors and lights exist so other drivers can see your truck — its full width, its length, and its movement — day or night. When one or more of those required devices is absent, damaged, or otherwise failing to meet the standard, an inspector can write you up under 393.11A1-LSML. This applies to everything from side marker lights and clearance lights to the reflectors mounted on your trailer.
The code sits under the broader Vehicle Maintenance category, and it carries a CSA severity weight of 3. That's not the heaviest weight on the scale, but it is a real mark against your safety record that stays in the system and factors into your carrier's CSA scores.
What our enforcement data actually shows
Across our database of 13 million+ inspections, 393.11A1-LSML has generated 8,606 all-time citations. In the last 12 months alone, our inspection records show 4,999 citations — meaning more than half of all historical citations for this code have occurred in just the past year. The last 90 days account for 890 of those, which tells you enforcement activity on this code is sustained and active, not a historical artifact.
Here is the number that should put your mind at ease about immediate consequences: the all-time out-of-service rate for 393.11A1-LSML is 0.0%. Out of 8,606 citations, only 4 vehicles were placed out of service — that rounds to essentially zero. Compare that to the all-FMCSR average OOS rate of 31.4% across all codes in our database, and you can see this violation is not the type that typically shuts you down at the roadside. That said, 0.0% does not mean zero risk — it means the risk is extremely low, and you still have a violation on your record.
The code ranks #246 out of 3,036 FMCSR codes by citation volume. That puts it in the top 8% of most-cited codes nationally. Inspectors know what to look for, and they are writing this up regularly.
Looking at the monthly trend in our records, citation volume peaked at 532 in September 2025 and has ranged between 326 and 532 citations per month over the past year. There is no dramatic seasonal spike, which means inspectors are treating lighting compliance as a year-round priority — not just a winter enforcement push.
Who gets cited most
In the last 180 days, California leads all states with 360 citations, followed by Florida with 263 and the federal jurisdiction category (US) with 186. New York recorded 118 citations and Georgia 107 over the same period. Every one of those top states shows a 0.0% OOS rate, which is consistent with the national picture for this code.
OOS rate variation across these top states is not material — all are at 0.0% — so geography doesn't change your odds of being parked. What geography does change is how often inspectors are looking. California and Florida together account for more than a third of citations in that 180-day window, so if you run lanes through those states frequently, your exposure to this citation is proportionally higher.
Our data shows fleets such as Federal Express Corporation (USDOT 86876) with 24 all-time citations and Jesus Pedro Perez Carrillo (USDOT 1159851) with 22 citations appearing at the top of the all-time carrier list. High citation counts across a fleet often reflect high inspection exposure as much as anything else — carriers with more inspections simply accumulate more citations across all codes.
How severe is this compared to similar codes
To put 393.11A1-LSML in context, look at what else lives in the Vehicle Maintenance category. The peer code 393.9(a) — Inoperable required lamps — has 660,737 all-time citations in our database with a 15.4% OOS rate. That is a dramatically more dangerous citation from a roadside consequences standpoint: one in seven vehicles cited under that code gets parked. Under 393.11A1-LSML, that almost never happens.
The parent code 393.11 — Lighting devices/reflectors — has 179,734 citations with a 1.8% OOS rate. Even that broader version of the same underlying issue carries a higher OOS rate than this specific subcode, which underscores how rarely 393.11A1-LSML results in an out-of-service order.
By contrast, 396.3(a)(1) — Inspection/repair/maintenance general — sits at 236,919 citations with a 45.3% OOS rate. That code will put you on the side of the road nearly half the time it's written. The lighting code you've been cited for operates in a completely different risk tier for roadside consequences, even though it still counts against your CSA record.
How to avoid it
Our data on co-occurring violations gives you a clear roadmap for what inspectors are finding alongside 393.11A1-LSML. In the last 90 days, 393.9A-LSML (Inoperable required lamps) appeared in 216 of the same inspections, and 393.9A-LIL appeared in 206. That pattern is telling you the same inspection that catches a missing reflector is also catching lamps that aren't functioning. Treat your pre-trip lighting check as a complete system review, not a box-check.
- Walk the full perimeter before every dispatch. Check every clearance light, side marker, and reflector on both the tractor and trailer. On Freightliner and FRHT units — the top two cited makes in our database with 1,439 and 562 citations respectively — pay close attention to the front clearance lights and cab marker lights, which are common failure points.
- Test trailer lighting at the plug, not just by sight. A light that looks intact may not be receiving power. Plug in and have someone confirm brake lights, turn signals, and markers are all responding.
- Check reflector mounting integrity. A reflector that has partially detached or is obscured by road grime may not meet the required visibility standard even if it is technically present.
- Carry spares. Our co-occurrence data shows 393.95F — stopped vehicle warning devices — appeared in 103 of the same inspections as 393.11A1-LSML in the last 90 days. Inspectors who find lighting issues are already looking at your emergency equipment. Make sure your triangle kit is accessible and complete.
- Resolve the periodic inspection gap. 396.17C-PI (No proof of periodic inspection) was found alongside this code in 217 shared inspections over the last 90 days — the most common co-occurring violation. If your annual inspection documentation isn't current and on the vehicle, that's a separate citation waiting to happen every time lighting brings an inspector to your door.
- Don't ignore windshield condition. Our records show 393.78A-WS appeared in 122 of the same inspections. If an inspector is already writing lighting violations, they are doing a thorough walk-around. A cracked or obstructed windshield discovered during the same stop becomes another line on the citation sheet.