What 393.136 means in plain language
FMCSR 393.136 addresses the securement of large boulders on commercial trucks. When you haul boulders or similar cargo, federal regulations require that they be properly and adequately secured to prevent them from shifting, falling, or causing damage during transit.
This isn't about a minor strap being loose—inspectors are looking for evidence that large stone material is restrained in a way that will hold it in place under normal driving conditions, including braking, turning, and acceleration. The violation is issued when an inspector finds that boulders are either not secured at all or secured in a manner that inspectors determine is insufficient to meet federal standards.
If you haul aggregates, decorative stone, or landscape boulders, this code directly applies to your operation. Even a single improperly restrained boulder can trigger a citation.
What our enforcement data actually shows
Across our 13 million inspection records, 393.136 is cited infrequently but with severe enforcement consequences. All-time, we have recorded 49 citations for this code. Over the last 12 months, that's 8 citations, and in the last 90 days, 2 citations have been issued.
The critical enforcement pattern: our data shows a 91.8% out-of-service rate for 393.136 violations. This means that in 45 of 49 all-time citations, the truck was immediately removed from service. For context, the average out-of-service rate across all FMCSR codes is 31.4%, making 393.136 nearly three times as likely to result in an out-of-service citation. Of the 49 violations recorded, only 4 trucks were allowed to continue operating.
While citation volume is low, the enforcement response is aggressive. Most recent enforcement activity shows seasonal or project-based patterns: 2 citations in May 2025, 2 in July 2025, 1 each in October 2025, December 2025, February 2026, and 1 in March 2026 (which was not placed out of service).
Who gets cited most
Geographically, enforcement is concentrated in a small number of states. Over the last 180 days, Texas accounts for 2 citations with a 50.0% out-of-service rate (1 out of 2 trucks removed from service), and New Mexico has 1 citation with a 100.0% out-of-service rate.
Our records show that carriers engaged in rock hauling and landscaping material transport appear more frequently in 393.136 enforcement. NOVA LINES INC (USDOT 2559423) leads with 3 all-time citations, followed by CORNERSTONE ROCK HAULING LLC (USDOT 2586789), SHAWN & COREY TRANSPORT INC (USDOT 988066), and VAL JOHNSON (USDOT 480561), each with 2 citations. These patterns reflect the cargo type risk, not carrier negligence—rock and boulder transport inherently involves higher securement complexity.
How severe is this compared to similar codes
Within the Vehicle Maintenance category, 393.136 is exceptionally severe relative to citation volume. Consider the comparison:
393.9 (Inoperable Required Lamp) has 180,097 all-time citations with a 6.9% out-of-service rate. It's cited thousands of times more frequently but results in out-of-service orders far less often.
396.17C (No Proof of Periodic Inspection) shows 212,081 citations with a 0.0% out-of-service rate—almost never results in immediate removal from service despite high volume.
393.47E (Slack Adjuster Defective) records 180,363 citations with 0.0% out-of-service rate, similarly non-punitive in enforcement.
By this comparison, 393.136 is enforced with exceptional rigor. Inspectors treat boulder securement failures as safety-critical defects warranting immediate out-of-service action in nearly all cases.
How to avoid it
Boulder and large aggregate securement requires deliberate pre-trip inspection and proper loading practice:
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Conduct a dedicated cargo securement walk-around before departure. Physically verify that each boulder or large stone is prevented from moving forward, backward, and sideways. Look for gaps between cargo and the bed walls or between boulders themselves where movement could occur.
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Use redundant securement methods. Multiple tiedowns, chains, or straps at different anchor points are more effective than a single point of contact. Inspect all hardware for wear or damage before loading—our co-occurring violation data shows that damaged tiedown equipment (393.104B) frequently appears alongside boulder securement failures.
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Inspect your truck's structural integrity and restraint attachment points. Our data indicates that frame cracks or looseness (393.201A) co-occur with securement violations. A cracked frame or loose bed structure cannot reliably anchor cargo. Walk around the truck bed and cargo area and confirm that all anchor points, D-rings, and rail systems are secure and not cracked or deformed.
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Check brake and steering systems as part of your pre-trip. Vehicles cited for boulder securement violations frequently have concurrent brake issues (393.45DLUV — brake tubing/hoses) and steering defects (393.53B). These mechanical issues may indicate overall vehicle maintenance neglect that extends to cargo securement rigging. A full walk-around should include brake hoses, slack adjusters, steering play, and coupling security.
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Verify lighting and coupling systems. Defective towing or coupling systems (393.55E) and inoperable lights (393.9) co-occur with securement violations, often signaling a vehicle that should not be on the road. Ensure all reflectors, clearance lights, and brake lights function. Check coupling tightness and safety chains.
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Know your vehicle type and load capacity. Flatbeds and stake trucks (Freightliner, Kenworth, and Fontaine trailers appear most frequently in our enforcement data) have different cargo securing requirements based on deck configuration. Confirm that your equipment is rated for the weight and size of boulders you're hauling, and that your securement method is appropriate to your truck and trailer type.
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If you're fatigued or unwell, do not operate. Our data shows that driver fitness violations (392.2WC) occasionally co-occur with securement failures. Fatigue impairs judgment about whether cargo is properly secured and increases the risk that you'll miss a defect during pre-trip.
Since 393.136 carries a 91.8% out-of-service rate, a single citation will almost certainly stop your revenue for at least 24 hours. Prevention is far cheaper than an out-of-service order or the potential liability if improperly secured cargo causes an accident.