What 393.87(a) means in plain language
When your cargo extends beyond the rear or sides of your vehicle, federal regulations require you to mark that overhang with warning flags. The rule exists because a projecting load—whether it's lumber, pipe, steel, or any other long material—creates a hazard that other drivers may not see until it's too late.
The flags themselves aren't optional decoration. They must be present, visible, and properly placed at the outermost point of any projection. If an inspector walks up to your truck and can't find them, or finds them in the wrong location, you're looking at a 393.87(a) citation.
This is a straightforward load-securement and visibility issue. It doesn't require a judgment call about whether something might be dangerous—if the load projects and the flag isn't there, the violation is written.
What our enforcement data actually shows
Across our database of 13 million+ roadside inspections, 393.87(a) has generated 2,735 all-time citations, ranking it #466 out of 3,036 FMCSR codes by citation volume. That puts it in the top 15% of all codes for how often it gets written—not the most common citation on the road, but far from rare.
The number that should get your attention is the out-of-service rate. Our inspection records show that 1,440 of those 2,735 citations resulted in the driver being placed out of service, for an all-time OOS rate of 52.7%. To put that in perspective, the all-FMCSR average OOS rate across all codes is 31.4%. This code runs 21.3 percentage points above that average.
That's a significant gap. It means that when an inspector writes this violation, they place the driver out of service more than half the time—not occasionally, but as the dominant outcome.
One important context note: 393.87(a) is not formally designated as an OOS-eligible code under the standard OOS criteria. The 52.7% rate in our data reflects inspector discretion applied in combination with other conditions observed at the time of inspection. Still, the number is real and it matters to your planning.
For recent activity, our database shows 0 citations in the last 90 days and 0 in the last 12 months. Enforcement of this specific code has gone quiet in the near term, but the all-time record of 2,735 citations demonstrates that inspectors have enforced it consistently over time and can again.
Who gets cited most
The carrier data in our records provides a window into which fleets encounter this violation most often. Our data shows fleets such as US LBM LOGISTICS LLC (USDOT 90308) with 8 citations, GOLDEN STATE LUMBER INC (USDOT 438620) with 5 citations, and M & R FORESTRY SERVICE INC (USDOT 2565594) with 5 citations appearing at the top of the all-time list. The pattern across the top carriers is telling: lumber, timber, and building materials haulers dominate the list. This makes sense given the nature of the violation—long, flat loads of wood and structural material are exactly the type of cargo that projects beyond the vehicle bed.
Vehicle make data reinforces this picture. Our inspection records show Peterbilt (143 citations under the PTRB designation, plus an additional 70 under the PETERBILT designation) and Freightliner (138 citations under FRHT, plus 91 under FREIGHTLIN) leading the vehicle make breakdown. These are common workhorses in logging, construction, and flatbed operations—precisely the sectors hauling the kinds of loads that require flagging.
How severe is this compared to similar codes
To understand where 393.87(a) sits in the broader enforcement landscape, it helps to compare it against peer codes in the Vehicle Maintenance category.
393.9(a) — Inoperable required lamps has been cited 660,737 times in our database, with a 15.4% OOS rate. That's 241 times more citations than 393.87(a), but the OOS rate is 37.3 percentage points lower. Inspectors write lamp violations constantly, but they rarely park the truck over them. With missing load flags, the calculus is clearly different.
396.3(a)(1) — Inspection, repair, and maintenance (general) comes in at 236,919 citations and a 45.3% OOS rate. That 45.3% rate is high—but our inspection records show 393.87(a)'s 52.7% rate still exceeds it, meaning missing load flags carry a heavier OOS consequence than even a general maintenance failure finding.
393.78 — Windshield condition defective has 157,894 citations on record but only a 0.3% OOS rate. That contrast illustrates how differently inspectors treat visibility-related violations depending on the specific hazard involved. A cracked windshield almost never parks a truck; a load projecting into traffic without a flag very often does.
In short, 393.87(a) punches above its weight on OOS outcomes relative to how frequently it's cited.
How to avoid it
The citation is preventable. Every single 393.87(a) violation written in our database started with a driver who either didn't check for flags before leaving or lost them in transit. Here's what to build into your pre-trip and en-route process:
- Check your load overhang before you move. If any part of your load extends past the rear or sides of the vehicle, flags are required—period. Measure or visually confirm the extent of projection before you pull out of the yard.
- Carry spare flags on every load trip. Flags get lost, blow off, or get damaged in transit. Keep extras in your cab or toolbox so you can replace them at a fuel stop or before a scale.
- Include flag placement in your pre-trip checklist specifically for flatbed and open-deck loads. Peterbilt and Freightliner trucks dominate our citation data for this code—if you're running one of these platforms on a flatbed or lowboy, build the flag check into your standard walkround.
- Inspect flags after any load shift or road vibration event. Long hauls over rough roads can loosen or dislodge flags. A quick check at your next stop takes 30 seconds.
- When loading lumber, pipe, or structural steel, position flags as part of the tie-down process—not as an afterthought. The carrier data in our database is dominated by wood and building-materials haulers. If that's your freight, make flag placement a standard step in your load-out procedure, not something you remember after the straps are tight.
- Know what counts as a projection. Any overhang beyond the rear of the vehicle or beyond the side of the load bed triggers the requirement. When in doubt, flag it.