Prevention FAQ — FMCSR 393.134: Cargo Securement – Large Boulders

Inspectors are evaluating whether large boulders in aggregate loads are secured in a manner that prevents forward, rearward, and lateral movement — and whether the securement method (blocking, cribbing, chains, or equivalent) is appropriate for the size and shape of each boulder.

Our inspection records show enforcement is heavily concentrated in Texas, which accounts for 286 citations in the last 180 days alone — more than five times the next-highest state (North Carolina at 50). Illinois and Iowa, while lower volume at 18 and 2 citations respectively, both posted 100.0% out-of-service rates in that same window, meaning every inspection in those states resulted in a driver being shut down on the spot.

Inspectors in high-volume states appear especially alert to loads where individual large rocks are irregular in shape and could roll or shift. Expect scrutiny at weigh stations and targeted roadside stops in construction corridors.

Build these steps into every pre-trip for boulder loads:

1. Load survey before departure — Walk the load and identify any boulder that can roll independently. Flag any stone larger than a basketball as requiring individual securement, not just aggregate stacking.
2. Blocking and cribbing check — Confirm blocking or cribbing is in contact with the boulder on at least two sides and cannot shift.
3. Chain and tie-down count — Verify the number and working load limit of chains or straps meets the aggregate weight requirement. Inspect each anchor point for cracks, wear, or deformation.
4. Load stability shake test — With the tailgate or stake sides secured, physically push corner boulders to confirm no movement.
5. Visual re-check after first mile — Pull over after the first 1–2 miles and verify nothing has shifted. Vibration and road irregularities during initial travel are a primary source of securement loosening before a longer haul begins.

Document the pre-trip with time-stamped notes and driver signature.

Drivers should carry on every boulder haul:

• A signed pre-trip inspection record that specifically references cargo securement (generic DVIR entries like "cargo OK" are insufficient — note the specific securement method used).
• Load-specific securement plan or job ticket describing boulder sizes, weight estimates, and securement method selected.
• Equipment certification for chains/straps showing working load limit ratings.

Carriers should retain:

• Pre-trip and post-trip DVIRs for at least 90 days.
• Load manifests or quarry/job site tickets identifying aggregate type and estimated weight.
• Driver training records showing completion of cargo securement training specific to large irregularly shaped materials.
• Repair and maintenance records for all securement hardware (chains, binders, anchor points).

Our inspection records show that 96.8% of all-time 393.134 citations resulted in an out-of-service order, so documentation that demonstrates a good-faith inspection process is critical for both DataQs challenges and safety audits.

The co-occurrence data from the last 90 days reveals three systemic patterns worth building root-cause programs around:

1. Driver fatigue and fitness (392.2RG — 34 shared inspections): This is the most frequent pairing. When a driver is impaired by fatigue, pre-trip quality degrades. The implication is that securement failures on boulder loads are downstream of hours-of-service and dispatch pressure problems, not just training gaps.

2. Deferred maintenance mindset (393.9 — 31 shared inspections, inoperable required lamp): Lighting defects and cargo securement failures appearing together suggest a culture where vehicles are dispatched with known deficiencies. If a driver tolerates a burned-out lamp, they're likely also accepting marginal cargo securement.

3. Missing periodic inspection records (396.17C — 19 shared inspections): When carriers lack proof of periodic inspection, it indicates an overall maintenance program gap — not just a paperwork problem. Vehicles without documented inspection histories are statistically more likely to accumulate unresolved defects across all systems.

An out-of-service order under 393.134 means the driver cannot move the vehicle until the securement deficiency is corrected. Before return to service:

1. On-site correction — Re-secure boulders using compliant blocking, cribbing, or chaining. A supervisor or designated safety personnel — not the driver alone — should sign off on the corrected load.
2. Equipment inspection — If a chain, binder, or anchor point failed, remove it from service and document the failure. Do not reuse hardware that allowed a load shift.
3. Post-repair documentation — Create a written record of exactly what was corrected, by whom, and at what time. This becomes part of the incident file.
4. Carrier confirmation before moving — The dispatcher or safety manager should confirm via signed checklist that the corrected load has been inspected before authorizing departure. Given the 96.8% OOS rate on this code, a second-party verification step is justified for every boulder haul, not just post-citation.

Run a structured post-event review within 48 hours of the citation:

1. Reconstruct the load — Pull the load manifest, pre-trip DVIR, and any photographs from the inspection. Determine whether the securement was compliant when the driver departed or whether it degraded in transit.
2. Driver debrief — Ask the driver specifically: Was the pre-trip securement check completed? Was there a post-first-mile re-check? Were any concerns communicated to dispatch before departure?
3. Equipment audit — Inspect all chains, binders, and anchor points on the cited vehicle and, within 30 days, extend that audit to all vehicles in the boulder-hauling fleet.
4. Training gap assessment — Cross-reference the driver's training records against the co-occurring violations found in this inspection. If 392.2RG (fatigue) was also cited, the review must include a HOS records pull and dispatch log review.
5. CSA scoring impact — Document the severity weight (7 points for this code) and projected BASIC impact so leadership understands the urgency of corrective action timelines.

393.134 carries a CSA severity weight of 7 — placing it among the higher-severity citations in the Vehicle Maintenance BASIC. For context, our inspection records show this code is ranked #344 out of 3,036 FMCSR codes by all-time citation volume (4,888 total), which means it's not an obscure edge case — FMCSA has seen it often enough to weight it heavily.

With a 96.8% out-of-service rate (compared to the all-FMCSR average of 31.4%), nearly every citation also generates an OOS event, which compounds the BASIC impact beyond the severity weight alone. An OOS event amplifies the points calculation in the SMS algorithm.

For carriers with multiple drivers on boulder or aggregate hauls — the top ten cited carriers in our database are all waste and aggregate haulers — repeated 393.134 citations can push the Vehicle Maintenance BASIC above intervention thresholds quickly. Prevention is materially cheaper than remediation at that point.

Our inspection records show MACK trucks lead all vehicle makes with 893 all-time citations under 393.134, followed by Peterbilt (549) and Kenworth (360). These are the dominant platforms in heavy vocational and aggregate hauling fleets — the citation concentration here reflects fleet composition, not a defect in those specific makes. But it does tell you exactly where to focus training deployment.

Priority training topics for drivers operating these platforms on boulder hauls:

• Boulder-specific securement methods — Standard flatbed cargo training is insufficient. Drivers need hands-on instruction in cribbing, blocking, and chaining for irregular, high-density materials.
• Load dynamics at speed — Heavy boulders in aggregate loads behave differently from palletized freight. Training should cover how vibration and braking forces act on unsecured large stones.
• Pre-trip documentation specificity — Drivers completing generic DVIRs without noting specific securement hardware used are creating a documentation gap. Train drivers to record chain count, binder type, and anchor condition by name.
• First-mile re-inspection habit — Build this into standard operating procedure and verify compliance during ride-along evaluations.

A DataQs challenge is worth pursuing when the inspection record contains a factual error or the citation was issued without the conditions required for a violation — not simply because the citation is inconvenient.

Scenarios that support a strong challenge:

• The securement method used was compliant and documented in the pre-trip DVIR, but the inspector cited the load anyway. Photographic evidence of the load as loaded strengthens this claim significantly.
• The load consisted of material that does not meet the regulatory definition of large boulders subject to 393.134 (e.g., processed aggregate below threshold size), and the carrier has weight tickets or quarry documentation to support that.
• The inspector recorded the wrong code — particularly possible when a load has a general cargo securement issue rather than a large-boulder-specific one.

Challenges that typically fail: Arguments that the driver "didn't think it would shift" or that no accident occurred. The inspection standard is condition at time of inspection, not outcome. Given the 96.8% OOS rate on this code, inspectors writing it are highly confident in their findings — challenge the facts, not the judgment call.

Our inspection records show 813 citations in the last 12 months and 146 in the last 90 days — a pace suggesting sustained enforcement pressure year-round. The monthly trend data shows citation volume peaked at 102 in July 2025, with a secondary peak of 89 in October 2025, indicating elevated risk during summer construction season and fall project closeout periods.

Recommended audit cadence:

• Monthly unannounced load audits during May–October (the high-citation window). A supervisor should observe a driver loading and securing boulders without advance notice and rate compliance against the written checklist.
• Quarterly equipment audits year-round — inspect all chains, binders, anchor rings, and blocking materials fleet-wide. Retire any hardware showing wear, deformation, or illegible WLL markings.
• Annual full program review — compare DVIR records, citation history, and training completion rates. If any driver on boulder hauls has not completed specific large-boulder securement training in the past 12 months, that is a gap the audit should flag before an inspector does.